Tsagaan-Olom, Mongolia

1. Thu7 PM44°12 mph
2. 8 PM42°10 mph
3. 9 PM40°9 mph
4. 10 PM40°7 mph
5. 11 PM39°9 mph
6. Fri12 AM38°11 mph
7. 1 AM37°13 mph
8. 2 AM36°17 mph
9. 3 AM34°18 mph
10. 4 AM33°17 mph
11. 5 AM33°15 mph
12. 6 AM33°14 mph
13. 7 AM32°15 mph
14. 8 AM33°18 mph
15. 9 AM35°20 mph
16. 10 AM37°21 mph
17. 11 AM39°21 mph
18. 12 PM41°20 mph
19. 1 PM42°19 mph
20. 2 PM44°18 mph
21. 3 PM45°16 mph
22. 4 PM45°15 mph
23. 5 PM44°13 mph
24. 6 PM42°10 mph
25. 7 PM40°8 mph
26. 8 PM38°7 mph
27. 9 PM36°6 mph
28. 10 PM35°7 mph
29. 11 PM33°6 mph
30. Sat12 AM31°6 mph
31. 1 AM30°6 mph
32. 2 AM29°6 mph
33. 3 AM28°7 mph
34. 4 AM27°8 mph
35. 5 AM25°9 mph
36. 6 AM24°9 mph
37. 7 AM25°9 mph
38. 8 AM30°9 mph
39. 9 AM35°12 mph
40. 10 AM40°14 mph
41. 11 AM44°15 mph
42. 12 PM48°13 mph
43. 1 PM51°12 mph
44. 2 PM53°14 mph
45. 3 PM53°15 mph
46. 4 PM53°13 mph
47. 5 PM51°15 mph
48. 6 PM47°13 mph

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

1. TodayOct 144°33°Light snow—wind 12 mph
2. FriOct 245°25°Light snow showers—0.03 inwind 21 mph
3. SatOct 353°31°Partly cloudy—wind 15 mph
4. SunOct 451°36°Clear—wind 7 mph
5. MonOct 560°46°Partly cloudy—wind 8 mph
6. TueOct 662°43°Cloudy—wind 15 mph
7. WedOct 748°32°Partly cloudy—0.01 inwind 12 mph
8. ThuOct 845°33°Clear—wind 12 mph
9. FriOct 952°34°Clear—wind 6 mph
10. SatOct 1055°45°Mostly clear—wind 19 mph
11. SunOct 1138°38°No forecast—wind 23 mph
12. MonOct 12~38°22°Model mean
13. TueOct 13~41°23°Model mean
14. WedOct 14~47°25°Model mean
15. ThuOct 15~41°29°Model mean
16. FriOct 16~35°29°Model mean

• Feels like36°
• WindNNW 12 mph
• Humidity40%
• Dew point21°
• Pressure29.98 inHg
• UV index0 · Lowclear-sky peak 4 Friday
• Sunrise and sunsetSunrise · Sunset · set
• Moonrise8:19 PMMoonset 12:18 PM
• Moon phaseWaning gibbous78% lit

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.

NWS gridGFSGEFS ± spreadECMWFECMWF AI

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

ECMWF ensemble meteogram

10 daysTemperature plume

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.

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

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.

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

• Thu 9 PM to Fri 12 AM 3 hours, every hour within the rules
• Fri 6 PM to Sat 3 AM 9 hours, every hour within the rules
• Sat 8 PM to Mon 7 PM 47 hours, some with delta T between 8 and 10 °C
• Tue 1 AM to 1 PM 12 hours, every hour within the rules
• Tue 7 PM to Wed 7 AM 12 hours, every hour within the rules
• Thu 1 AM to 7 AM 6 hours, every hour within the rules
• Thu 1 PM to 7 PM 6 hours, every hour within the rules
• Fri 1 AM to Sat 7 AM 30 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 Wednesday, rated good.

Periods in bold fall within an hour of sunrise or sunset. The weather’s side is the fishing index · Solunar tables for Tsagaan-Olom, by month

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. Tonight33° · NW 7–17 mph

   Light snow. Low near 1°C. Northwest wind 12 to 28 km/h.

2. Friday45° · NW 13–21 mph

   Light snow showers. High near 7°C. Northwest wind 21 to 34 km/h.

3. Friday Night25° · SSW 6–9 mph

   Clear. Low near -4°C. Southsouthwest wind 9 to 15 km/h.

4. Saturday53° · SE 9–15 mph

   Partly cloudy. High near 12°C. Southeast wind 14 to 24 km/h.

5. Saturday Night31° · NNW 5–13 mph

   Mostly clear. Low near 0°C. Northnorthwest wind 8 to 21 km/h.

6. Sunday51° · SSE 5–7 mph

   Clear. High near 11°C. Southsoutheast wind 8 to 11 km/h.

7. Sunday Night36° · S 3–7 mph

   Clear. Low near 2°C. South wind 5 to 12 km/h.

8. Monday60° · ESE 6–7 mph

   Partly cloudy. High near 16°C. Eastsoutheast wind 10 to 12 km/h.

9. Monday Night46° · ENE 2–6 mph

   Cloudy. Low near 8°C. Eastnortheast wind 4 to 9 km/h.

10. Tuesday62° · S 9–16 mph

    Cloudy. High near 17°C. South wind 14 to 25 km/h.

11. Tuesday Night43° · NW 7 mph

    Cloudy. Low near 6°C. Northwest wind around 12 km/h.

12. Wednesday48° · WNW 4–11 mph

    Partly cloudy. High near 9°C. Westnorthwest wind 7 to 17 km/h.

13. Wednesday Night32° · NW 4–12 mph

    Mostly clear. Low near 0°C. Northwest wind 6 to 19 km/h.

14. Thursday45° · N 2–4 mph

    Clear. High near 7°C. North wind 3 to 6 km/h.

15. Thursday Night33° · E 3–6 mph

    Clear. Low near 1°C. East wind 5 to 9 km/h.

16. Friday52° · E 5 mph

    Clear. High near 11°C. East wind around 8 km/h.

17. Friday Night34° · WSW 4–6 mph

    Mostly clear. Low near 1°C. Westsouthwest wind 6 to 9 km/h.

18. Saturday55° · S 2–11 mph

    Mostly clear. High near 13°C. South wind 3 to 18 km/h.

19. Saturday Night45° · WSW 19–24 mph

    Partly cloudy. Low near 7°C. Westsouthwest wind 31 to 38 km/h.

20. Sunday38° · NW 11 mph

    No forecast. High near 4°C. Northwest wind around 18 km/h.

Climate of Tsagaan-Olom: 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.