Colchester, IL Weather & Growing Conditions
Tonight
50°F
Showers And Thunderstorms Likely
Showers and thunderstorms likely before 1am. Mostly cloudy. Low around 50, with temperatures rising to around 52 overnight. South wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 60%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 50°F | Showers And Thunderstorms Likely | 10 to 15 mph S | 59% |
| Wednesday | 55°F | Mostly Cloudy | 15 mph SW | 14% |
| Wednesday Night | 43°F | Mostly Cloudy | 10 mph SW | 4% |
| Thursday | 56°F | Partly Sunny | 10 to 15 mph W | 12% |
| Thursday Night | 42°F | Mostly Cloudy then Chance Rain Showers | 5 to 10 mph NW | 27% |
| Friday | 53°F | Mostly Cloudy | 5 to 10 mph N | 12% |
| Friday Night | 35°F | Mostly Cloudy | 0 to 5 mph N | 0% |
| Saturday | 53°F | Mostly Sunny | 0 to 5 mph NW | 1% |
| Saturday Night | 35°F | Mostly Clear | 0 to 5 mph W | 2% |
| Sunday | 59°F | Sunny | 5 to 10 mph W | 9% |
| Sunday Night | 36°F | Mostly Clear | 0 to 5 mph W | 4% |
| Monday | 64°F | Sunny | 5 to 10 mph SW | 1% |
| Monday Night | 41°F | Mostly Clear | 5 mph W | 0% |
| Tuesday | 65°F | Sunny | 5 mph NW | 0% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Colchester, IL
Last spring frost
Apr 21
First fall frost
Oct 19
Growing season
180 days
Hardiness zone
6a
Explore more for Colchester, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, La Harpe, Il (13.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.