Thomson, IL Weather & Growing Conditions
Today
86°F
Mostly Sunny then Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms after 5pm. Mostly sunny. High near 86, with temperatures falling to around 84 in the afternoon. Southwest wind 5 to 10 mph. Chance of precipitation is 20%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 86°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 to 10 mph SW | 20% |
| Tonight | 66°F | Showers And Thunderstorms Likely | 0 to 5 mph NW | 90% |
| Wednesday | 76°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 0 to 5 mph N | 72% |
| Wednesday Night | 60°F | Showers And Thunderstorms Likely | 0 to 5 mph N | 68% |
| Thursday | 79°F | Chance Rain Showers then Mostly Sunny | 0 to 5 mph NE | 32% |
| Thursday Night | 59°F | Mostly Clear | 0 mph | 6% |
| Friday | 82°F | Mostly Sunny | 0 to 5 mph S | 4% |
| Friday Night | 64°F | Mostly Clear | 0 to 5 mph S | 9% |
| Saturday | 85°F | Sunny | 0 to 10 mph SW | 11% |
| Saturday Night | 69°F | Mostly Clear then Slight Chance Showers And Thunderstorms | 5 mph S | 21% |
| Sunday | 87°F | Slight Chance Showers And Thunderstorms | 5 to 10 mph SW | 21% |
| Sunday Night | 69°F | Chance Showers And Thunderstorms | 5 to 10 mph S | 40% |
| Monday | 86°F | Chance Showers And Thunderstorms | 5 to 10 mph S | 38% |
| Monday Night | 69°F | Chance Showers And Thunderstorms | 5 to 10 mph NW | 41% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Thomson, IL
Last spring frost
Apr 13
First fall frost
Oct 26
Growing season
195 days
Hardiness zone
5b
Explore more for Thomson, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Fulton L&D #13, Il (7.6 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.