Thomson, IL Weather & Growing Conditions
Tonight
64°F
Mostly Cloudy then Chance Showers And Thunderstorms
A chance of showers and thunderstorms between midnight and 4am, then showers and thunderstorms. Some of the storms could produce heavy rain. Mostly cloudy. Low around 64, with temperatures rising to around 66 overnight. Southeast wind 5 to 10 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 64°F | Mostly Cloudy then Chance Showers And Thunderstorms | 5 to 10 mph SE | 75% |
| Saturday | 80°F | Showers And Thunderstorms | 5 to 10 mph S | 79% |
| Saturday Night | 62°F | Showers And Thunderstorms | 5 to 10 mph NW | 76% |
| Sunday | 70°F | Rain Showers | 10 to 15 mph NE | 76% |
| Sunday Night | 54°F | Rain Showers Likely | 10 to 15 mph NE | 61% |
| Monday | 65°F | Chance Rain Showers | 10 to 15 mph NE | 47% |
| Monday Night | 50°F | Chance Rain Showers | 10 to 15 mph NE | 45% |
| Tuesday | 63°F | Chance Rain Showers | 10 to 15 mph NE | 32% |
| Tuesday Night | 47°F | Partly Cloudy | 5 to 10 mph NE | 7% |
| Wednesday | 68°F | Mostly Sunny | 5 to 10 mph NE | 3% |
| Wednesday Night | 50°F | Partly Cloudy | 0 to 5 mph NE | 2% |
| Thursday | 69°F | Mostly Sunny | 0 to 5 mph NE | 5% |
| Thursday Night | 52°F | Partly Cloudy | 0 to 5 mph NE | 5% |
| Friday | 71°F | Mostly Sunny | 0 to 5 mph NE | 5% |
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 Sep 19, 2026.