Collinsville, IL Weather & Growing Conditions
This Afternoon
72°F
Rain
Rain and a slight chance of thunderstorms. Cloudy. High near 72, with temperatures falling to around 67 in the afternoon. South wind around 13 mph, with gusts as high as 28 mph. Chance of precipitation is 90%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 72°F | Rain | 13 mph S | 93% |
| Tonight | 55°F | Rain | 9 to 15 mph S | 98% |
| Wednesday | 64°F | Chance Rain Showers then Mostly Cloudy | 7 to 14 mph W | 12% |
| Wednesday Night | 46°F | Partly Cloudy | 6 mph SW | 0% |
| Thursday | 66°F | Sunny | 5 to 10 mph W | 1% |
| Thursday Night | 46°F | Mostly Cloudy | 5 mph NW | 8% |
| Friday | 58°F | Mostly Cloudy | 6 to 10 mph NW | 7% |
| Friday Night | 41°F | Partly Cloudy | 2 to 7 mph N | 1% |
| Saturday | 56°F | Mostly Sunny | 5 mph NW | 0% |
| Saturday Night | 38°F | Partly Cloudy | 2 mph NW | 0% |
| Sunday | 62°F | Sunny | 2 to 7 mph W | 8% |
| Sunday Night | 39°F | Mostly Clear | 5 mph W | 5% |
| Monday | 66°F | Sunny | 2 to 7 mph SW | 2% |
| Monday Night | 43°F | Mostly Clear | 5 mph SW | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Collinsville, IL
Last spring frost
Apr 8
First fall frost
Oct 26
Growing season
200 days
Hardiness zone
7a
Explore more for Collinsville, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Cahokia St Louis Ap, Il (12.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.