37.1930, -83.1880

1. Mon12 AM55°1 mph
2. 1 AM54°0 mph
3. 2 AM53°0 mph
4. 3 AM53°0 mph
5. 4 AM52°0 mph
6. 5 AM51°0 mph
7. 6 AM50°0 mph
8. 7 AM49°0 mph
9. 8 AM49°0 mph
10. 9 AM54°0 mph
11. 10 AM58°1 mph
12. 11 AM65°1 mph
13. 12 PM69°2 mph
14. 1 PM73°2 mph
15. 2 PM75°3 mph
16. 3 PM75°3 mph
17. 4 PM75°3 mph
18. 5 PM73°3 mph
19. 6 PM71°2 mph
20. 7 PM67°1 mph
21. 8 PM63°0 mph
22. 9 PM61°0 mph
23. 10 PM59°1 mph
24. 11 PM58°1 mph
25. Tue12 AM57°1 mph
26. 1 AM57°1 mph
27. 2 AM56°1 mph
28. 3 AM55°1 mph
29. 4 AM55°1 mph
30. 5 AM55°1 mph
31. 6 AM54°1 mph
32. 7 AM54°1 mph
33. 8 AM54°1 mph
34. 9 AM56°1 mph
35. 10 AM63°1 mph
36. 11 AM69°0 mph
37. 12 PM73°0 mph
38. 1 PM76°1 mph
39. 2 PM79°1 mph
40. 3 PM79°1 mph
41. 4 PM78°0 mph
42. 5 PM78°0 mph
43. 6 PM74°0 mph
44. 7 PM70°1 mph
45. 8 PM66°1 mph
46. 9 PM64°1 mph
47. 10 PM62°2 mph
48. 11 PM60°2 mph

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

1. TodaySep 2875°54°Sunny0%wind 3 mph
2. TueSep 2980°58°Mostly Sunny0%wind 2 mph
3. WedSep 3084°63°Sunny0%wind 3 mph
4. ThuOct 186°66°Mostly Sunny7%wind 5 mph · gusts 10 mph
5. FriOct 282°61°Chance Rain Showers42%0.20 inwind 5 mph
6. SatOct 374°61°Chance Rain Showers39%0.43 inwind 3 mph
7. SunOct 473°60°Rain Showers Likely58%0.94 inwind 3 mph

• Feels like55°
• WindCalm
• Radar over this pointno reading
• Humidity86%
• Dew point51°
• Pressure—
• UV index—
• Air quality—
• Visibility—
• Sunrise and sunsetSunrise · Sunset · not yet up
• Moonrise8:12 PMMoonset 9:33 AM
• Moon phaseWaning gibbous95% lit

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.

Each rating says which span it is for: the rest of today’s daylight, tonight, or the next 24 hours.

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

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 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.

This hour: no-fly (low cloud limits height (107.51), night: lighting and night training required (107.29)). Next good stretch: Tue 8 AM to 7 PM, 11 hours.

Today: civil twilight for Part 107 6:56 AM to sunrise 7:26 AM, and sunset 7:20 PM to 7:50 PM. Anti-collision lighting is required in those minutes and at night.

Good Caution No-fly

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.

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

• Mon 2 PM to 6 PM 4 hours, every hour within the rules
• Wed 7 AM to 10 AM 3 hours, every hour within the rules
• Wed 1 PM to 3 PM 2 hours, some with delta T between 8 and 10 °C
• Wed 10 PM to Fri 6 AM 32 hours, some with delta T between 8 and 10 °C

Good Marginal No

Field days

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.

The best-rated day this week is Monday, rated good.

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.

1. Overnight49° · NNW 1 mph

   Mostly clear. Low around 49, with temperatures rising to around 51 overnight. North northwest wind around 1 mph.

2. Monday75° · NNW 0–3 mph

   Sunny. High near 75, with temperatures falling to around 73 in the afternoon. North northwest wind 0 to 3 mph.

3. Monday Night54° · E 2 mph

   Mostly clear. Low around 54, with temperatures rising to around 55 overnight. East wind around 2 mph.

4. Tuesday80° · ENE 1 mph

   Mostly sunny. High near 80, with temperatures falling to around 78 in the afternoon. East northeast wind around 1 mph.

5. Tuesday Night58° · E 2 mph

   Mostly clear. Low around 58, with temperatures rising to around 59 overnight. East wind around 2 mph.

6. Wednesday84° · S 3 mph

   Sunny, with a high near 84.

7. Wednesday Night63° · S 3 mph

   Mostly clear, with a low around 63.

8. Thursday86° · 1% · SSW 5 mph

   Mostly sunny, with a high near 86.

9. Thursday Night66° · 15% · S 5 mph

   A slight chance of rain showers after 2am. Partly cloudy, with a low around 66. Chance of precipitation is 20%.

10. Friday82° · 42% · WSW 5 mph

    A chance of rain showers. Partly sunny, with a high near 82. Chance of precipitation is 40%.

11. Friday Night61° · 42% · N 3 mph

    A chance of rain showers. Mostly cloudy, with a low around 61. Chance of precipitation is 40%.

12. Saturday74° · 39% · NE 3 mph

    A chance of rain showers. Mostly cloudy, with a high near 74. Chance of precipitation is 40%.

13. Saturday Night61° · 51% · E 3 mph

    A chance of rain showers. Mostly cloudy, with a low around 61. Chance of precipitation is 50%.

14. Sunday73° · 58% · SSE 3 mph

    Rain showers likely. Mostly cloudy, with a high near 73. Chance of precipitation is 60%.

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.

Fetching the discussion…

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

Reading the outlooks…

The last spring freeze (32°F) usually comes around April 18 and the first fall freeze around October 28: a growing season of about 191 days.

One fall in ten brings a freeze by October 17; one spring in ten still has one after May 2.

Climate of 37.19, -83.19: normals, records and every month

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.

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.

Reading the station’s record…