Current weather · Sep 26, 11:49 PM EDT

38.6290, -77.4390

63°

Chance of light rainFeels like 63° · Humidity 78%NWS forecast for this hour; no recent station reportForecast by NWS Baltimore/Washington · grid 84,57
High
70°
Low
59°
Rain today
82%
Sunrise
7:01 AM
Sunset
7:00 PM

Hour by hour

NWS forecast grid

Scroll sideways for more hours. Pick an hour for every number.

Every hour as a table48 hours
TimeWeatherTemperatureFeels likeDew pointHumidityChanceAmountSnowDirWindGustSky coverThunderPressureVisibilityCeiling
Sat 11 PMChance of light rain63°63°56°78%46%0.00 inNNW10 mph12 mph97%1%—10 mi4,300 ft
Sun 12 AMChance of light rain62°62°56°81%37%0.00 inNNW10 mph12 mph93%1%—10 mi4,200 ft
Sun 1 AMChance of light rain62°62°56°81%26%0.00 inNNW12 mph18 mph88%1%—10 mi4,500 ft
Sun 2 AMSlight chance of light rain62°62°56°81%17%NNW12 mph18 mph84%—10 mi4,500 ft
Sun 3 AM61°61°56°84%9%NNW12 mph18 mph85%—10 mi4,700 ft
Sun 4 AM61°61°56°84%1%NNW10 mph12 mph87%—10 mi5,200 ft
Sun 5 AM61°61°55°81%3%NNW10 mph12 mph88%—10 mi5,300 ft
Sun 6 AM60°60°55°84%2%NW10 mph12 mph82%—10 mi5,600 ft
Sun 7 AM59°59°55°87%2%NW9 mph10 mph77%—10 mi6,000 ft
Sun 8 AM59°59°55°87%2%NW10 mph12 mph71%—10 mi6,300 ft
Sun 9 AM61°61°57°87%4%NW13 mph21 mph70%—10 mi6,700 ft
Sun 10 AM62°62°57°84%6%NW16 mph25 mph69%—10 mi7,100 ft
Sun 11 AM63°63°58°84%7%NW18 mph30 mph68%1%—10 mi7,500 ft
Sun 12 PM64°64°58°81%8%NW18 mph30 mph76%1%—10 mi6,300 ft
Sun 1 PM64°64°59°84%9%NW18 mph30 mph85%1%—10 mi5,200 ft
Sun 2 PMSlight chance of light rain64°64°60°87%20%NW18 mph30 mph93%—5 mi4,000 ft
Sun 3 PMSlight chance of light rain64°64°61°90%21%NW17 mph28 mph94%—5 mi3,700 ft
Sun 4 PMSlight chance of light rain65°65°62°90%18%NNW17 mph28 mph96%—5 mi3,300 ft
Sun 5 PM63°63°62°97%9%NNW17 mph28 mph97%—10 mi3,000 ft
Sun 6 PM64°64°61°90%6%NNW16 mph25 mph92%—10 mi3,300 ft
Sun 7 PM64°64°61°90%4%NW14 mph22 mph88%—10 mi3,600 ft
Sun 8 PM63°63°60°90%13%NW13 mph21 mph83%—10 mi3,200 ft
Sun 9 PM63°63°60°90%9%NW10 mph12 mph83%—10 mi3,000 ft
Sun 10 PM63°63°61°93%0%NW9 mph10 mph82%—10 mi2,900 ft
Sun 11 PM62°62°61°97%1%NW8 mph9 mph82%—10 mi2,700 ft
Mon 12 AM62°62°61°97%0%NW8 mph9 mph85%—10 mi
Mon 1 AMChance of light rain showers61°61°61°100%25%NW8 mph9 mph89%—5 mi
Mon 2 AM61°61°60°97%0%NW8 mph9 mph92%—10 mi
Mon 3 AM61°61°60°97%2%NW8 mph9 mph92%—10 mi
Mon 4 AM61°61°60°97%1%NW7 mph8 mph93%—10 mi
Mon 5 AM61°61°60°97%0%NW7 mph8 mph93%—10 mi
Mon 6 AM61°61°59°93%0%NW7 mph8 mph88%—10 mi
Mon 7 AM60°60°59°96%1%NW7 mph8 mph83%—10 mi
Mon 8 AM60°60°60°100%1%NW7 mph8 mph78%—10 mi
Mon 9 AM62°62°61°97%1%NW8 mph9 mph78%—10 mi
Mon 10 AM63°63°62°97%1%NW10 mph12 mph79%—10 mi
Mon 11 AM65°65°62°90%1%NW13 mph21 mph79%—10 mi
Mon 12 PM66°66°63°90%1%NW13 mph21 mph81%—10 mi
Mon 1 PM68°68°63°84%1%NW13 mph21 mph82%—10 mi
Mon 2 PM68°68°64°87%2%NW12 mph18 mph84%—10 mi
Mon 3 PM69°69°65°87%2%NW12 mph18 mph85%—10 mi
Mon 4 PM70°70°65°84%2%NNW10 mph12 mph87%—10 mi
Mon 5 PM70°70°65°84%2%NNW10 mph12 mph88%—10 mi
Mon 6 PM70°70°64°81%2%NNW8 mph9 mph86%—10 mi
Mon 7 PM68°68°64°87%2%NNW7 mph8 mph85%—10 mi
Mon 8 PM67°67°63°87%0%NNW6 mph7 mph83%—10 mi
Mon 9 PM66°66°63°90%0%NW5 mph6 mph75%—10 mi
Mon 10 PM65°65°63°93%0%NW5 mph6 mph68%—10 mi

The next 16 days

NWS grid published Sep 26, 10:52 PM EDT to day 8, the National Blend of Models to day 11, the mean of GFS, ECMWF, ECMWF AI to day 16
  1. TodaySep 2670°59°Chance Light Rain82%0.03 inwind 17 mph · gusts 28 mph
  2. SunSep 2767°60°Mostly Cloudy then Slight Chance Light Rain37%wind 18 mph · gusts 30 mph
  3. MonSep 2871°61°Mostly Cloudy25%wind 13 mph · gusts 21 mph
  4. TueSep 2975°60°Mostly Sunny1%wind 9 mph
  5. WedSep 3081°61°Sunny1%wind 6 mph · gusts 12 mph
  6. ThuOct 183°64°Mostly Sunny3%wind 6 mph
  7. FriOct 281°63°Partly Sunny then Slight Chance Rain Showers17%wind 6 mph · gusts 13 mph
  8. SatOct 374°61°Chance Rain Showers41%wind 6 mph
  9. SunOct 471°59°National Blend50%0.81 inwind 8 mph · gusts 16 mph
  10. MonOct 569°53°National Blend36%0.48 inwind 9 mph · gusts 18 mph
  11. TueOct 666°51°National Blend15%0.21 inwind 7 mph · gusts 14 mph
  12. WedOct 7~64°50°Model mean0.28 in
  13. ThuOct 8~69°51°Model mean0.13 in
  14. FriOct 9~66°50°Model mean
  15. SatOct 10~66°48°Model mean
  16. SunOct 11~61°38°Model mean

Right now

NWS grid for this hour · UV from the EPA · air quality from AirNow
  • Feels like63°
  • WindNNW 10 mph
  • Radar over this pointno reading
  • Humidity78%
  • Dew point56°
  • Pressure—
  • UV index—
  • Air quality—
  • Visibility10 mi
  • Sunrise and sunsetSunrise · Sunset · set
  • Moonrise6:50 PMMoonset 6:53 AM
  • Moon phaseFull moon100% lit

The National Blend of Models

NOAA NBM v5.0 · run of Sep 26, 8:00 PM EDT

NOAA’s weighted blend of every model it runs, to eleven days, with the chances the grid above does not carry. Where the local office’s grid reaches, its figure sits beneath the blend’s; where it does not, the blend stands alone.

  1. TodaySep 26—59°NWS grid 70° / 59°rain 43%wind 13 mph · gusts 26 mph
  2. SunSep 2767°60°NWS grid 67° / 60°rain 23%wind 15 mph · gusts 32 mph
  3. MonSep 2870°60°NWS grid 71° / 61°rain 11%wind 10 mph · gusts 20 mph
  4. TueSep 2975°60°NWS grid 75° / 60°rain 1%wind 5 mph
  5. WedSep 3080°62°NWS grid 81° / 61°rain 2%wind 6 mph · gusts 12 mph
  6. ThuOct 183°65°NWS grid 83° / 64°rain 6%wind 6 mph · gusts 12 mph
  7. FriOct 281°62°NWS grid 81° / 63°rain 21%wind 6 mph · gusts 12 mph
  8. SatOct 373°60°NWS grid 74° / 61°rain 49%thunder 11%0.08 inwind 6 mph · gusts 12 mph
  9. SunOct 471°59°Beyond the NWS gridrain 50%0.81 inwind 8 mph · gusts 16 mph
  10. MonOct 569°53°Beyond the NWS gridrain 36%0.48 inwind 9 mph · gusts 18 mph
  11. TueOct 666°51°Beyond the NWS gridrain 15%0.21 inwind 7 mph · gusts 14 mph
  12. WedOct 766°—Beyond the NWS gridrain 13%wind 7 mph · gusts 13 mph
59°73°86°SunMonTueWedThuFriSat

BlendNWS gridChance of rain, hourly

The models, side by side

HRRR Sep 26, 8:00 PM EDT · GFS Sep 26, 2:00 PM EDT · GEFS Sep 26, 2:00 PM EDT · ECMWF Sep 26, 8:00 AM EDT · ECMWF AI Sep 26, 8:00 AM EDT

Each line is one model’s own forecast at its own grid cell: three kilometers for HRRR, a quarter of a degree for the global models, which can sit a few hundred meters above or below the town. Where they agree the forecast is settled; where they part is where it is not.

50°73°95°SunMonTueWedThuFriSat

DayNWS gridHRRRGFSGEFSECMWFECMWF AI
Today Sep 2670° 59°0.03 in~59° 56°0.02 in~70° 56°0.17 in~70° 57°0.22 in70° 58°0.30 in~73° 59°0.22 in
Sun Sep 2767° 60°68° 57°69° 57°0.03 in64° 59°0.04 in64° 60°0.12 in~65° 60°0.21 in
Mon Sep 2871° 61°71° 59°71° 59°70° 60°0.03 in70° 61°~71° 62°0.03 in
Tue Sep 2975° 60°—73° 62°0.01 in76° 59°0.01 in75° 62°~76° 63°0.02 in
Wed Sep 3081° 61°—82° 59°81° 58°81° 59°~82° 62°
Thu Oct 183° 64°—88° 61°85° 62°82° 66°~88° 63°
Fri Oct 281° 63°—80° 68°83° 67°0.03 in~77° 68°0.02 in~89° 66°0.02 in
Sat Oct 374° 61°—77° 62°0.02 in75° 63°0.02 in~64° 56°0.60 in~68° 62°0.23 in
Sun Oct 4——72° 66°0.67 in71° 60°0.34 in~60° 55°0.87 in~60° 55°1.88 in
Mon Oct 5——73° 52°0.19 in70° 60°0.45 in~64° 61°0.59 in~69° 60°0.07 in
Tue Oct 6——66° 46°~64° 54°0.19 in~63° 54°~65° 58°
Wed Oct 7——~69° 48°—~64° 46°~59° 56°0.83 in
Thu Oct 8——~75° 51°—~72° 48°~60° 55°0.40 in
Fri Oct 9——~59° 42°—~72° 54°~66° 53°
Sat Oct 10——~56° 37°—~70° 58°0.02 in~73° 48°
Sun Oct 11——~61° 38°—~66° 64°0.33 in~52° 48°

A ~ marks a high or low read from six-hourly steps, which miss the true extreme by a degree or two.

ECMWF ensemble meteogram

ECMWF ensemble meteogram for this place: box plots of cloud cover, precipitation, wind speed and temperature from the 51 ensemble members for ten days.
Rendered by ECMWF from its 51-member ensemble, in metric units: each box spans the middle half of the members, the whiskers the rest, the line the control run. A forecast, not an observation. © ECMWF, CC BY 4.0.

The next 90 days

NOAA GHCN normals and records at Manassas Municipal(Awos) (HEF) · Climate Prediction Center outlooks

No forecast has skill day by day past about two weeks, and this page does not print one. Where the models stop, the calendar takes over: the 1991 to 2020 normal for each date, the record high and low ever set on it, and where the Climate Prediction Center leans warm, cool, wet or dry over the coming weeks, the month and the season. A site that shows a high for a date three months out is showing you this normal with a wobble.

The forecast reaches Sun Oct 11, from the NWS grid, then the National Blend, then the mean of the global models. Beyond it the lines are the calendar.

Climate Prediction Center (CPC) temperature lean40%warmer 40% · Oct 202633% chance above normal · Oct to Dec0°20°40°60°80°100°TodayOct 1Nov 1Dec 1

Forecast high and lowNormal high and lowRecord high and lowCPC leans warmer than normalCPC near normal or equal chances

Week ofNormalWarmest on recordColdest on recordTemperature leanPrecipitation lean
Sep 2672° / 52°96° (1998)31° (1993)no outlookno outlook
Oct 372° / 49°94° (2007)26° (1974)40% chance above normal · days 6 to 1040% chance above normal · days 6 to 10
Oct 1069° / 45°88° (1989)23° (1988)40% chance above normal · Oct 2026equal chances · Oct 2026
Oct 1766° / 44°87° (2016)20° (1972)40% chance above normal · Oct 2026equal chances · Oct 2026
Oct 2463° / 44°86° (2023)15° (1969)40% chance above normal · Oct 2026equal chances · Oct 2026
Oct 3162° / 38°84° (1982)16° (1991)33% chance above normal · Oct to Dec33% chance above normal · Oct to Dec
Nov 759° / 35°81° (2023)16° (1973)33% chance above normal · Oct to Dec33% chance above normal · Oct to Dec
Nov 1454° / 34°81° (1993)13° (1986)33% chance above normal · Oct to Dec33% chance above normal · Oct to Dec
Nov 2154° / 32°77° (1979)9° (1989)33% chance above normal · Oct to Dec33% chance above normal · Oct to Dec
Nov 2853° / 33°75° (2006)-0° (1967)33% chance above normal · Oct to Dec33% chance above normal · Oct to Dec
Dec 545° / 28°79° (1998)1° (2002)33% chance above normal · Oct to Dec33% chance above normal · Oct to Dec
Dec 1248° / 31°76° (2006)3° (1989)33% chance above normal · Oct to Dec33% chance above normal · Oct to Dec
Dec 1948° / 29°71° (2013)-2° (1989)33% chance above normal · Oct to Dec33% chance above normal · Oct to Dec

Health and activities

Rules of thumb over the next 24 hours of forecast, the warnings in force, the station’s report, air quality and pollen

None of these is a measurement. Each is a rating of the forecast ahead, and of what is happening at the point right now, against what the activity or the ailment is known to mind, and each names the figure that decided it. An ailment or a pest is rated as a risk, low to extreme; an activity, a chore or a journey as a condition, poor to ideal.

The sun is down, so each rating says which span it is for: tomorrow’s daylight, tonight, or the next 24 hours.

Health

  • Arthritisnext 24 hModeratehumid
  • Sinus pressurenext 24 hLowsteady conditions
  • Common coldtomorrowLowmild
  • FlutomorrowLowmild
  • Migrainenext 24 hLowsteady conditions
  • Asthmanext 24 hLowclean air
  • Heat stresstomorrowLowmild
  • SunburntomorrowLowweak sun
  • Frostbitenext 24 hLowmild
  • SleepingtonightIdealcool, quiet night

Outdoors

  • RunningtomorrowVery goodhumid
  • HikingtomorrowIdealfine conditions
  • BikingtomorrowVery goodwind
  • GolftomorrowIdealfine conditions
  • FishingtomorrowIdealfine conditions
  • Boating and paddlingtomorrowFairwind
  • Beach and pooltomorrowFaircool
  • CampingtonightGoodrain overnight
  • StargazingtonightPoorovercast

Travel

  • Air travelnext 24 hIdealclear skies
  • Drivingnext 24 hIdealclear roads

Home and garden

  • Lawn mowingtomorrowIdealfine conditions
  • GardeningtomorrowIdealfine conditions
  • Outdoor entertainingtomorrowGoodhumid
  • Drying laundry outsidetomorrowPoorhumid
  • Painting and outdoor projectstomorrowGoodhumid
  • FrosttonightLowmild

Pests

  • MosquitoestomorrowHighwarm
  • TickstomorrowVery highwarm
  • Indoor pestsnext 24 hLowmild
  • Outdoor peststomorrowHighhumid

Stargazing

Worked out from the NWS hourly forecast and the sun and moon

Tonight has no dark, clear hour without a bright moon in this forecast. Rated poor.

Night ofRatingDarkClear hoursClear and moonlessMoon litTransparency (est.)DewStrongest wind
SaturdayPoor8:29 PM to 5:33 AM0 of 10None100%13 mph
SundayPoor8:27 PM to 5:34 AM0 of 10None98%10 h13 mph
MondayPoor8:25 PM to 5:35 AM0 of 10None94%9 h6 mph
TuesdayFair8:24 PM to 5:36 AM4 of 10None87%Poor9 h0 mph
WednesdayPoor8:22 PM to 5:37 AM0 of 10None80%7 h3 mph
ThursdayPoor8:21 PM to 5:38 AM0 of 10None71%1 h6 mph
FridayPoor8:19 PM to 5:39 AM0 of 10None60%2 h3 mph

Dark is the sun 18 degrees below the horizon; where it never gets that low, 12 degrees, marked nautical. Clear is sky cover of 20% or less. A bright moon is one above the horizon with a quarter or more of its disc lit. Transparency in the table is estimated from surface humidity (70% and 85% mark fair and poor) and visibility, since the forecast carries no haze or high cloud moisture. Seeing and transparency by hour, where shown, are Environment and Climate Change Canada’s astronomy forecast (regional model; seeing from cloud, wind shear, turbulence near the ground and the surface temperature trend; transparency from the moisture through the whole air column), under the Open Government Licence - Canada. Dew is the air within 2 °C of its dew point. Excellent is four or more clear moonless hours with good transparency; good is three; fair is one, or two clear hours.

Golden hour and blue hour

Computed from the sun and moon positions
DayBlue hour, morningGolden hour, morningGolden hour, eveningBlue hour, evening
Sat6:35 AM to 6:45 AM6:45 AM to 7:36 AM6:25 PM to 7:16 PM7:16 PM to 7:27 PM
Sun6:36 AM to 6:46 AM6:46 AM to 7:37 AM6:24 PM to 7:15 PM7:15 PM to 7:25 PM
Mon6:36 AM to 6:47 AM6:47 AM to 7:38 AM6:22 PM to 7:13 PM7:13 PM to 7:24 PM
Tue6:37 AM to 6:48 AM6:48 AM to 7:39 AM6:20 PM to 7:12 PM7:12 PM to 7:22 PM
Wed6:38 AM to 6:49 AM6:49 AM to 7:40 AM6:19 PM to 7:10 PM7:10 PM to 7:20 PM
Thu6:39 AM to 6:49 AM6:49 AM to 7:41 AM6:17 PM to 7:09 PM7:09 PM to 7:19 PM
Fri6:40 AM to 6:50 AM6:50 AM to 7:42 AM6:16 PM to 7:07 PM7:07 PM to 7:17 PM
NESWSRSSMRMS
  • SR Sunrise 7:01 AM, 91° E
  • SS Sunset 7:00 PM, 269° W
  • MR Moonrise 6:50 PM, 83° E
  • MS Moonset 6:53 AM, 273° W
  • Full moon, 100% lit

Golden hour is the sun between 6 degrees above the horizon and 4 degrees below it; blue hour is the sun between 4 and 6 degrees below. These are the definitions timeanddate.com and PhotoPills use. Directions are degrees clockwise from true north, where the sun’s upper edge and the moon’s center cross a flat horizon; hills and buildings change both. None means the sun does not reach that height on the day; all day means it stays inside the band.

Drone flying

NWS hourly forecast, SWPC Kp, FAA TFRs and 14 CFR Part 107

This hour: fly with caution (chance of rain, night: lighting and night training required (107.29)). Next good stretch: Mon 8 AM to 11 AM, 3 hours.

Today: civil twilight for Part 107 6:31 AM to sunrise 7:01 AM, and sunset 7:00 PM to 7:30 PM. Anti-collision lighting is required in those minutes and at night.

Sat
Sun12 AM6 AM12 PM6 PM
Mon12 AM6 AM12 PM6 PM

Good Caution No-fly

HourVerdictWind (mph)400 ft est. (mph)Gust (mph)RainVisibilityCloud allowsTempKpWhy
Sat 11 PMCaution10151646%10 mi400 ft63°chance of rain, night: lighting and night training required (107.29)
Sun 12 AMCaution10151637%10 mi400 ft62°chance of rain, night: lighting and night training required (107.29)
Sun 1 AMCaution12172426%10 mi400 ft62°gusts near or over your limit, night: lighting and night training required (107.29)
Sun 2 AMCaution12172417%10 mi400 ft62°gusts near or over your limit, night: lighting and night training required (107.29)
Sun 3 AMCaution1217249%10 mi400 ft61°gusts near or over your limit, night: lighting and night training required (107.29)
Sun 4 AMCaution1015161%10 mi400 ft61°night: lighting and night training required (107.29)
Sun 5 AMCaution1015163%10 mi400 ft61°night: lighting and night training required (107.29)
Sun 6 AMCaution1015162%10 mi400 ft60°night: lighting and night training required (107.29)
Sun 7 AMCaution912132%10 mi400 ft59°civil twilight: lighting required (107.29)
Sun 8 AMGood1013142%10 mi400 ft59°nothing against it
Sun 9 AMNo-fly1318264%10 mi400 ft61°gusts near or over your limit, wind at 400 ft near or over your limit
Sun 10 AMNo-fly1623336%10 mi400 ft62°gusts near or over your limit, wind at 400 ft near or over your limit
Sun 11 AMNo-fly1827387%10 mi400 ft63°wind at 400 ft near or over your limit, gusts near or over your limit, ground wind near or over your limit
Sun 12 PMNo-fly1827388%10 mi400 ft64°wind at 400 ft near or over your limit, gusts near or over your limit, ground wind near or over your limit
Sun 1 PMNo-fly1827389%10 mi400 ft64°wind at 400 ft near or over your limit, gusts near or over your limit, ground wind near or over your limit
Sun 2 PMNo-fly18273820%5 mi400 ft64°wind at 400 ft near or over your limit, gusts near or over your limit, ground wind near or over your limit
Sun 3 PMNo-fly17253521%5 mi400 ft64°wind at 400 ft near or over your limit, gusts near or over your limit
Sun 4 PMNo-fly17253518%5 mi400 ft65°wind at 400 ft near or over your limit, gusts near or over your limit
Sun 5 PMNo-fly1725359%10 mi400 ft63°wind at 400 ft near or over your limit, gusts near or over your limit
Sun 6 PMNo-fly1623336%10 mi400 ft64°gusts near or over your limit, wind at 400 ft near or over your limit, civil twilight: lighting required (107.29)
Sun 7 PMNo-fly1420284%10 mi400 ft64°gusts near or over your limit, wind at 400 ft near or over your limit, night: lighting and night training required (107.29)
Sun 8 PMNo-fly13182613%10 mi400 ft63°gusts near or over your limit, wind at 400 ft near or over your limit, night: lighting and night training required (107.29)
Sun 9 PMCaution1015169%10 mi400 ft63°night: lighting and night training required (107.29)
Sun 10 PMCaution913150%10 mi400 ft63°night: lighting and night training required (107.29)

Flight restrictions nearby

Reading the FAA’s temporary flight restrictions.

Flight restrictions on the map. TFRs are not the whole picture: controlled airspace around airports needs LAANC authorization. Check the FAA’s B4UFLY.

Wind at 400 ft is estimated from the 10 m forecast by the power law, with exponents for each Pasquill stability class (Irwin 1979, rural, as in EPA dispersion models; the class from wind, sun height and cloud, after Turner 1970); gusts keep the ground gust’s margin. Caution from three quarters of your limit; the default 24 mph is the wind resistance printed for common sub-250 g drones. 14 CFR 107.51: “The minimum flight visibility, as observed from the location of the control station must be no less than 3 statute miles” and at least “500 feet below the cloud”. 14 CFR 107.29: “No person may operate a small unmanned aircraft system during periods of civil twilight unless the small unmanned aircraft has lighted anti-collision lighting visible for at least 3 statute miles”; civil twilight is the 30 minutes before sunrise and after sunset, in Alaska the Air Almanac’s. Kp: SWPC’s scales say satellite navigation problems may occur at G3 (Kp 7) and navigation is “degraded for hours” at G4 (Kp 8); Kp 5 is the typical app warning. Typical limits, not rules: rain chance 30% caution and 60% no-fly, thunder 10% and 20%, below 0 °C caution and −10 °C no-fly, over 40 °C caution. Your drone’s manual and the airspace come first.

Spraying and field work

Worked out from the NWS hourly forecast

Hours fit for spraying, and the days dry enough for fieldwork and hay, read from this forecast’s wind, gusts, humidity, temperature and rain.

Spraying windows

  • Tue 11 AM to 8 PM 9 hours, every hour within the rules
  • Wed 11 AM to 10 PM 11 hours, every hour within the rules
  • Thu 10 AM to 11 PM 13 hours, every hour within the rules
  • Fri 10 AM to 9 PM 11 hours, every hour within the rules
Sat
Sun12 AM6 AM12 PM6 PM
Mon12 AM6 AM12 PM6 PM
Tue12 AM6 AM12 PM6 PM

Good Marginal No

Field days

DayDaytimeChance of rainRainLowest humidityStrongest windDry days in a rowHay drying
SundayDry21%0.00 in81%18 mph6 d
MondayDry2%0.00 in81%13 mph5 d
TuesdayDry1%0.00 in74%9 mph4 d
WednesdayDry1%0.00 in65%6 mph3 d
ThursdayDry1%0.00 in58%6 mph2 d
FridayDry15%0.00 in67%6 mph1 d
SaturdayShowers possible30%0.00 in76%6 mph

Spraying: sustained wind 3 to 10 mph, the range US extension services and most labels give; gusts no more than 15 mph (this page’s limit); delta T (air minus wet-bulb temperature) 2 to 8 °C preferred and 8 to 10 °C marginal, from GRDC guidance, with the wet bulb by Stull’s formula; no hour at a 30% chance of rain or 0.25 mm forecast during the rain-free time. Follow the product label, which overrides all of this. Field days: dry is no daytime hour at a 30% chance and under 1 mm all day, wet is 6 mm (0.25 in) or more; soil moisture is not in the forecast, so ground still wet from earlier rain is not accounted for. Hay drying marks a dry day with humidity down to 50% and a breeze of 5 mph or more.

Solunar times

Computed from the moon’s position

The best-rated day this week is Saturday, rated best.

DayRatingMajor periodsMinor periodsMoonSunrise, sunset
Sat Best11:34 PM to 1:34 AM11:57 AM to 1:57 PM6:23 AM to 7:23 AM6:20 PM to 7:20 PM 100%7:01 AM, 7:00 PM
Sun Best12:20 AM to 2:20 AM12:43 PM to 2:43 PM7:31 AM to 8:31 AM6:46 PM to 7:46 PM 99%7:02 AM, 6:59 PM
Mon Good1:08 AM to 3:08 AM1:33 PM to 3:33 PM8:42 AM to 9:42 AM7:16 PM to 8:16 PM 95%7:03 AM, 6:57 PM
Tue Good2:00 AM to 4:00 AM2:27 PM to 4:27 PM9:56 AM to 10:56 AM7:51 PM to 8:51 PM 90%7:04 AM, 6:56 PM
Wed Poor2:56 AM to 4:56 AM3:25 PM to 5:25 PM11:10 AM to 12:10 PM8:35 PM to 9:35 PM 83%7:05 AM, 6:54 PM
Thu Fair3:56 AM to 5:56 AM4:27 PM to 6:27 PM12:23 PM to 1:23 PM9:29 PM to 10:29 PM 74%7:06 AM, 6:52 PM
Fri Fair4:58 AM to 6:58 AM5:30 PM to 7:30 PM1:28 PM to 2:28 PM10:33 PM to 11:33 PM 64%7:07 AM, 6:51 PM

Periods in bold fall within an hour of sunrise or sunset. The weather’s side is the fishing index

Major periods are two hours centered on the moon’s passage overhead and underfoot; minor periods are one hour centered on moonrise and moonset: the conventional durations of John Alden Knight’s solunar tables (1936). The rating is this site’s: one point to start, two more within a day and a half of a new or full moon (one more within three and a half days), and one more when a period falls within an hour of sunrise or sunset. The theory has mixed support in fisheries research; the times are exact astronomy.

In words

NWS forecast periods, as issued
  1. Tonight59° · 46% · NW 12 mph

    A chance of rain before 3am. Cloudy, with a low around 59. Northwest wind around 12 mph, with gusts as high as 18 mph. Chance of precipitation is 50%. New rainfall amounts less than a tenth of an inch possible.

  2. Sunday67° · 21% · NW 9–18 mph

    A slight chance of rain between 2pm and 5pm. Mostly cloudy, with a high near 67. Northwest wind 9 to 18 mph, with gusts as high as 30 mph. Chance of precipitation is 20%.

  3. Sunday Night60° · 25% · NW 7–16 mph

    A chance of rain showers between 1am and 2am. Cloudy, with a low around 60. Northwest wind 7 to 16 mph, with gusts as high as 25 mph. Chance of precipitation is 30%.

  4. Monday71° · 2% · NW 7–13 mph

    Mostly cloudy, with a high near 71. Northwest wind 7 to 13 mph, with gusts as high as 21 mph.

  5. Monday Night61° · 2% · NW 3–8 mph

    Mostly cloudy, with a low around 61. Northwest wind 3 to 8 mph.

  6. Tuesday75° · 1% · NW 3–9 mph

    Mostly sunny, with a high near 75.

  7. Tuesday Night60° · 1% · NE 0–5 mph

    Partly cloudy, with a low around 60.

  8. Wednesday81° · 1% · SW 0–6 mph

    Sunny, with a high near 81.

  9. Wednesday Night61° · 3% · S 5 mph

    Partly cloudy, with a low around 61.

  10. Thursday83° · 3% · SW 2–6 mph

    Mostly sunny, with a high near 83.

  11. Thursday Night64° · 5% · S 6 mph

    Partly cloudy, with a low around 64.

  12. Friday81° · 15% · SW 6 mph

    A slight chance of rain showers after 2pm. Partly sunny, with a high near 81. Chance of precipitation is 20%.

  13. Friday Night63° · 20% · N 5 mph

    A slight chance of rain showers. Mostly cloudy, with a low around 63. Chance of precipitation is 20%.

  14. Saturday74° · 30% · N 6 mph

    A chance of rain showers. Mostly cloudy, with a high near 74.

The forecaster’s discussion

NWS Baltimore/Washington · issued Sep 26, 9:42 PM EDT

Written by the forecaster on duty for their own colleagues and for anyone who wants to know why the forecast says what it says. It is not edited for the public, so it uses the office’s shorthand; it is also the most honest thing any weather service publishes.

What Has Changed

We continue to monitor rain moving off toward the south and west associated with a Nor'easter located offshore.

KEY Messages

1) A Nor'easter brings below normal temperatures, breezy conditions, and some rain at times through this weekend.

2) Warm and calm conditions next week before rainfall chances return by late next week.

Discussion

KEY MESSAGE 1...A Nor'easter brings below normal temperatures, breezy conditions, and some rain at times through this weekend.

A powerful Nor'easter continues to circulate offshore. As of 930 PM, a band of rainfall associated with this system is tracking off toward the southwest into Southern Maryland and Central Virginia. Behind this more focused band there a few showers that are lingering further northeast. Showers will continue to be possible on and off throughout the night, although there should be a tendency for the coverage of showers to decrease during the second half of the night. Winds will remain gusty out of the north to northwest overnight.

As the low center circles back into our area tomorrow, expect more rain late tomorrow morning through the day Sunday. Chances will be highest across the northeast part of the fcst area, and this period has the highest chance for rain to reach as far west as the Alleghenies. Northeast Maryland could see up to an inch of rain through the day Sunday. Wind gusts tomorrow will be 20-35 mph and up to 40 mph near the Chesapeake Bay.

While rain chances and wind gusts will likely start declining by Monday, cloud cover will likely remain stubbornly in place. The current forecast calls for upper 60s and lower 70s, but would not be surprised if they are a bit lower if clouds are thick. As winds shift more northwesterly, some upslope showers or drizzle will be possible in the Alleghenies.

KEY MESSAGE 2...Generally warm and benign weather next week before rainfall chances return by next weekend.

While rain chances and wind gusts decline on Monday, cloud cover remains stubborn, potentially limiting sunshine to start the week. Our current forecast calls for upper 60s and lower 70s, but could trend a bit cooler if a thicker cloud deck persists. As northwesterly wind shifts slightly further west, some upslope showers or drizzle will be possible in the Alleghenies.

Continuing into the beginning of next week, an upper level ridge advances overhead from the west, building high pressure at the surface through Wednesday. Overall, this pattern favors dry and gradually warmer conditions with highs in the 70s potentially creeping up into the low 80s late next week. One potential caveat could be Wednesday night into Thursday as a fast moving Clipper system passes by to our north. Given all of the forcing remains to the north and moisture return ahead of the system is weak, showers and thunderstorm potential appear negligible. The next chance for rain looks to be Friday and into next weekend ahead of an approaching cold front from Canada.

Aviation · 01Z Sunday Through Thursday

Off and on light showers are expected overnight, although coverage of those showers should tend to decrease during the second half of the night. Additional rain showers move in from the northeast tomorrow. The main impact will be the gusty N to NNW winds gusting 25-30 kt on Sunday. Some brief reductions in cigs are possible, but vsby restrictions are not anticipated.

Northeasterly to easterly winds continue to weaken on Tuesday and shift southerly by Wednesday. VFR conditions are forecast to prevail through the middle of next week, with no precipitation chances.

Marine

Occasional gale force gusts have been observed so far today, but the gradient remains tight and the latest ECMWF shows another surge in northerly winds tomorrow. Have extended the Gale Warning through tomorrow for the waters south of Drum Point where fetch will be longer and winds likely overperform. Otherwise, strong SCA conditions are expected through Monday.

Favorable, benign marine conditions expected through the middle of next week. Southerly channeling is possible over the open waters of the Chesapeake Bay on Wednesday, though still uncertain if those winds approach SCA strength.

Tides / Coastal Flooding

Water levels appear to have begun to slosh back at the bottom of the bay with increasing tidal anomalies seen now at Straits Point and Annapolis. Based on forecast trends from surge models, this prompted the issuance of a Coastal Flood Warning for St. Marys County for tonight's and Sunday's high tides. A Coastal Flood Watch was also issued for Anne Arundel County for Sunday's high tide. New Coastal Flood Advisory was issued for the City of Alexandria.

LWX Watches / Warnings / Advisories

DC...None. MD...Gale Warning until 10 PM EDT this evening for MDZ008. Small Craft Advisory until 6 PM EDT Sunday for MDZ008. Coastal Flood Advisory from 2 AM to 11 AM EDT Sunday for MDZ014. Coastal Flood Watch from Sunday afternoon through Sunday evening for MDZ014. Coastal Flood Advisory until 8 AM EDT Monday for MDZ016. Coastal Flood Advisory until 11 PM EDT this evening for MDZ017. Coastal Flood Warning until 6 PM EDT Sunday for MDZ017. Coastal Flood Advisory until 5 AM EDT Monday for MDZ018. VA...Coastal Flood Advisory until 8 AM EDT Monday for VAZ057. Coastal Flood Advisory until 11 AM EDT Monday for VAZ054. WV...None. MARINE...Gale Warning until 10 PM EDT this evening for ANZ530>533-537- 539>542. Small Craft Advisory until 6 PM EDT Sunday for ANZ530>533-537- 539>542. Gale Warning until 6 PM EDT Sunday for ANZ534-543. Small Craft Advisory until 6 PM EDT Sunday for ANZ535-536-538.

Hazardous weather outlook Sep 26, 4:23 PM EDT

The office’s own seven-day heads-up for spotters and emergency managers.

FLUS41 KLWX 262023
HWOLWX

Hazardous Weather Outlook
National Weather Service Baltimore MD/Washington DC
423 PM EDT Sat Sep 26 2026

ANZ530>543-DCZ001-MDZ008-011-013-014-016>018-504-506-508-
VAZ053>057-527-272030-
Chesapeake Bay north of Pooles Island MD-
Chesapeake Bay from Pooles Island to Sandy Point MD-
Chesapeake Bay from Sandy Point to North Beach MD-
Chesapeake Bay from North Beach to Drum Point MD-
Chesapeake Bay from Drum Point MD to Smith Point VA-
Tidal Potomac from Key Bridge to Indian Head MD-
Tidal Potomac from Indian Head to Cobb Island MD-
Tidal Potomac from Cobb Island MD to Smith Point VA-
Patapsco River including Baltimore Harbor-
Chester River to Queenstown MD-Eastern Bay-
Choptank River to Cambridge MD and the Little Choptank River-
Patuxent River to Broomes Island MD-
Tangier Sound and the inland waters surrounding Bloodsworth
Island-District of Columbia-Cecil-Southern Baltimore-
Prince Georges-Anne Arundel-Charles-St. Marys-Calvert-
Central and Southeast Montgomery-Central and Southeast Howard-
Southeast Harford-Fairfax-Arlington/Falls Church/Alexandria-
Stafford-Spotsylvania-King George-
Central and Southeast Prince William/Manassas/Manassas Park-
423 PM EDT Sat Sep 26 2026

This Hazardous Weather Outlook is for the Maryland portion of the
Chesapeake Bay, Tidal Potomac River, and I-95 corridor through
central Maryland, northern Virginia, and District of Columbia.

.DAY ONE...Tonight

A Gale Warning is in effect through 10 PM for the Chesapeake Bay 
and lower tidal Potomac River, while continuing overnight across
the lower Chesapeake Bay.

Tidal blowout conditions are possible through tonight north of 
Annapolis. A Low Water Advisory may be warranted.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Gale conditions are possible for portions of the tidal waters 
Sunday. 

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

$$

MDZ003>006-503-505-507-VAZ025>031-036>040-050-051-501-502-505>508-
526-WVZ050>053-055-272030-
Washington-Frederick-Carroll-Northern Baltimore-
Northwest Montgomery-Northwest Howard-Northwest Harford-Augusta-
Rockingham-Shenandoah-Page-Warren-Clarke-Nelson-Albemarle-Greene-
Madison-Rappahannock-Orange-Culpeper-Northern Fauquier-
Southern Fauquier-Western Loudoun-Eastern Loudoun-
Northern Virginia Blue Ridge-Central Virginia Blue Ridge-
Northwest Prince William-Hampshire-Morgan-Berkeley-Jefferson-
Hardy-
423 PM EDT Sat Sep 26 2026

This Hazardous Weather Outlook is for portions of eastern West
Virginia, northern and central Virginia, and central and western
Maryland.

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

$$

MDZ501-502-509-510-VAZ503-504-WVZ501>506-272030-
Extreme Western Allegany-Central and Eastern Allegany-
Western Garrett-Eastern Garrett-Western Highland-Eastern Highland-
Western Grant-Eastern Grant-Western Mineral-Eastern Mineral-
Western Pendleton-Eastern Pendleton-
423 PM EDT Sat Sep 26 2026

This Hazardous Weather Outlook is for the Allegheny Front
counties in western Maryland, eastern West Virginia, and Highland
County Virginia.

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

$$

The outlooks beyond

SPC, WPC, CPC and the Drought Monitor, read at this point

The national centers each publish a judgment the local grid does not carry. Read here at this exact coordinate.

Severe weather

  1. Day 1 · Sat Sep 26No risk area
  2. Day 2 · Sun Sep 27No risk area
  3. Day 3 · Mon Sep 28No risk area
  4. Day 4 · Tue Sep 29No risk area
  5. Day 5 · Wed Sep 30No risk area
  6. Day 6 · Thu Oct 1No risk area
  7. Day 7 · Fri Oct 2No risk area
  8. Day 8 · Sat Oct 3No risk area

Rainfall

  1. Day 1 · Sat Sep 260.01 in
  2. Day 2 · Sun Sep 27Under 0.01 in
  3. Day 3 · Mon Sep 28Under 0.01 in
  4. Day 4-5 · Sep 29–Sep 30Under 0.01 in
  5. Day 6-7 · Oct 1–Oct 20.01 in

The rainfall forecast on the map, days 1 to 7

Six to fourteen days

  1. Days 6–10 · Temperature40% chance above normalOct 2–Oct 6
  2. Days 6–10 · Precipitation40% chance above normalOct 2–Oct 6
  3. Days 8–14 · TemperatureNear normal most likelyOct 4–Oct 10
  4. Days 8–14 · Precipitation33% chance above normalOct 4–Oct 10

Drought

  1. Drought Monitor, map of Sep 22D0 Abnormally dry

Drought in this county: the map, the record since 2000 and the outlook

Frost and climate

NOAA 1991-2020 normals, Quantico Mcas

The last spring freeze (32°F) usually comes around March 28 and the first fall freeze around November 8: a growing season of about 226 days.

One fall in ten brings a freeze by October 28; one spring in ten still has one after April 8.

Climate of 38.63, -77.44: normals, records and every month

Everything else on the grid

NWS forecast grid · 27 elements

The forecast office edits about sixty fields for every cell of its grid. The common ones are above; these are the rest, as the daily extreme, for anyone who needs the mixing height, the fire danger or the swell.

ElementSatSunMonTueWedThuFriSat
HeatRisk max0 · Little1 · Minor1 · Minor1 · Minor1 · Minor1 · Minor1 · Minor1 · Minor
Wet bulb globe temperature max63°66°71°76°81°81°80°71°
Heat index max70°75°82°85°83°73°
Chance of thunder max6%1%0%1%1%3%6%6%
Cloud ceiling min4,300 ft2,700 ft
Visibility min6 mi5 mi5 mi10 mi10 mi10 mi5 mi
Mixing height max2,500 ft3,800 ft3,600 ft
Transport wind max22 mph24 mph14 mph
Atmospheric dispersion index max476236
Low visibility risk max467

Against the record

NOAA GHCN · Manassas Municipal(Awos) (HEF) · 7.6 mi away

Each forecast day against the same calendar date at the nearest long-record station: the 1991 to 2020 normal, and the record high and low with the year they were set.

DayForecastNormalRecord highRecord low
Sat Sep 2670° / 59°76° / 57°93° (2007)38° (1964)
Sun Sep 2767° / 60°78° / 57°96° (1998)35° (1984)
Mon Sep 2871° / 61°76° / 55°86° (1998)34° (1989)
Tue Sep 2975° / 60°72° / 52°89° (2019)34° (1978)
Wed Sep 3081° / 61°71° / 50°92° (1986)35° (1993)
Thu Oct 183° / 64°73° / 49°90° (1986)31° (1993)
Fri Oct 281° / 63°73° / 50°96° (2019)32° (1997)
Sat Oct 374° / 61°74° / 51°86° (2002)30° (1974)

Sun and moon

DayCivil twilightSunriseSunsetCivil twilightDaylightMoon
Sat6:35 AM7:01 AM7:00 PM7:27 PM11 h 59 min Full moon · 100% lit
Sun6:36 AM7:02 AM6:59 PM7:25 PM11 h 57 min Waning gibbous · 99% lit
Mon6:36 AM7:03 AM6:57 PM7:24 PM11 h 54 min Waning gibbous · 95% lit
Tue6:37 AM7:04 AM6:56 PM7:22 PM11 h 52 min Waning gibbous · 90% lit
Wed6:38 AM7:05 AM6:54 PM7:20 PM11 h 49 min Waning gibbous · 83% lit
Thu6:39 AM7:06 AM6:52 PM7:19 PM11 h 46 min Waning gibbous · 74% lit
Fri6:40 AM7:07 AM6:51 PM7:17 PM11 h 44 min Waning gibbous · 64% lit
Sat6:41 AM7:08 AM6:49 PM7:16 PM11 h 41 min Last quarter · 54% lit

Forecast from the National Weather Service forecast grid at api.weather.gov, updated by the local office through the day; the written periods and hourly digest are the NWS’s own. Outlooks from the Storm Prediction Center, the Weather Prediction Center and the Climate Prediction Center via NOAA’s map services. Records and normals from NOAA’s Global Historical Climatology Network. Sun and moon computed here. Place names from GeoNames (CC BY 4.0).

What is here

Seven days
The high, the low, the chance and amount of rain and snow, the wind and the forecaster’s words for each day and night, from the National Weather Service grid for the exact cell your town sits in.
Hour by hour
Temperature, what it feels like, dew point, humidity, chance and amount of precipitation, wind and gusts, sky cover, the chance of thunder, pressure, visibility and ceiling, as a chart and as a table, with nights shaded.
Everything else on the grid
The office edits about sixty fields for every cell. The ones the mainstream forecast pages leave out are here as a daily table: HeatRisk, wet bulb globe temperature, lightning activity, mixing height, transport wind, the fire weather indices, and at the coast the waves and swell.
The discussion
The Area Forecast Discussion the forecaster wrote to explain the forecast, in their own words, with the specialist annexes folded away. Also the office’s hazardous weather outlook.
Beyond the week
The Storm Prediction Center’s severe weather category for each of the next eight days, the Weather Prediction Center’s rainfall forecast to day seven and its winter storm severity, and the Climate Prediction Center’s odds for days six to fourteen, all read at your coordinate.
Against the record
Each forecast day beside the same date at the nearest long-record station: the thirty-year normal and the record high and low with their years, so a forecast high that would break a record says so.
The next 90 days
The forecast as far as the grid, the National Blend and the global models reach, and the calendar after that: the normal and the record for every date, with the Climate Prediction Center’s lean for the weeks, the month and the season drawn over them. No made-up highs for a date three months out.

Common questions

Where does this forecast come from?

From the National Weather Service forecast grid published at api.weather.gov, the same grid the local forecast office edits through the day and the source of every forecast on weather.gov. The written periods, the hourly digest and the forecaster’s discussion are the NWS’s own products, shown as issued. Nothing here is a blend a website made.

How far ahead does it go?

The grid runs seven days ahead, hour by hour for the first days and in three to six hour steps after that. The National Blend of Models carries the days to eleven and the global models to sixteen. Beyond that the page carries the national centers’ outlooks, severe weather to day eight, rainfall to day seven, and the Climate Prediction Center’s odds for the coming weeks, month and season, over a ninety-day calendar of the normal and the record for each date. No forecast has skill day by day past about two weeks, and this page does not print one.

Why is this different from the app on my phone?

Most forecast apps show a blend of models chosen by the company that makes the app. This page shows the forecast the local National Weather Service office issues, edited by the forecasters who will also issue the warnings, and it shows all of it rather than the six numbers that fit on a phone. The discussion explains the reasoning, which no app carries.

What is a place’s address here?

Every town has its own page, such as /forecast/us/oklahoma/oklahoma-city/, and every day at a town has one too. A ZIP code typed into the search goes to the town it belongs to. Any coordinate at all can be looked up, and the page names the nearest town.

What the weather actually was · Open the live radar · Where the data comes from