Colchester, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Colchester, a city in Mcdonough County, Illinois.
This Afternoon
69°F
Showers And Thunderstorms
Showers and thunderstorms. Cloudy, with a high near 69. South wind around 15 mph, with gusts as high as 30 mph. Chance of precipitation is 100%.
7-day forecast for Colchester
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 69°F | Showers And Thunderstorms | 15 mph S | 95% |
| Tonight | 50°F | Showers And Thunderstorms Likely | 10 to 15 mph S | 61% |
| 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 mph | 1% |
| Sunday | 59°F | Sunny | 0 to 10 mph W | 9% |
| Sunday Night | 36°F | Mostly Clear | 0 to 5 mph W | 4% |
| Monday | 63°F | Sunny | 5 to 10 mph SW | 1% |
| Monday Night | 40°F | Mostly Clear | 5 mph W | 0% |
Forecast source: National Weather Service (api.weather.gov) for Colchester (40.426, -90.792). Updated through the day.
Growing snapshot for Colchester
Last spring frost
Apr 21
First fall frost
Oct 19
Growing season
180 days
Hardiness zone
6a
More local growing data for Colchester: nearby ZIP 62326 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Adair
Bardolph
Blandinsville
Bushnell
Georgetown
Good Hope
Industry
Macomb
Prairie City
Sciota
Tennessee
Climate data from the nearest NOAA station, La Harpe, Il (13.8 mi from Colchester). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.