Collinsville, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Collinsville, a city in Madison County, Illinois.
This Afternoon
97°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms after 3pm. Sunny, with a high near 97. Heat index values as high as 105. South wind around 3 mph. Chance of precipitation is 30%.
7-day forecast for Collinsville
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 97°F | Chance Showers And Thunderstorms | 3 mph S | 26% |
| Tonight | 74°F | Slight Chance Showers And Thunderstorms then Mostly Clear | 6 mph SE | 24% |
| Saturday | 98°F | Mostly Sunny | 3 to 8 mph SW | 6% |
| Saturday Night | 74°F | Partly Cloudy | 5 mph S | 1% |
| Sunday | 94°F | Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms | 3 to 7 mph W | 19% |
| Sunday Night | 68°F | Slight Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 8 mph N | 58% |
| Monday | 81°F | Rain Showers Likely | 7 to 12 mph NE | 69% |
| Monday Night | 62°F | Showers And Thunderstorms Likely | 7 to 12 mph N | 69% |
| Tuesday | 72°F | Chance Rain Showers then Mostly Cloudy | 12 mph N | 28% |
| Tuesday Night | 55°F | Mostly Cloudy | 6 to 12 mph N | 6% |
| Wednesday | 75°F | Mostly Sunny | 9 mph N | 3% |
| Wednesday Night | 56°F | Partly Cloudy | 3 to 8 mph N | 2% |
| Thursday | 76°F | Mostly Sunny | 3 to 8 mph N | 3% |
| Thursday Night | 59°F | Partly Cloudy | 3 to 7 mph N | 3% |
Forecast source: National Weather Service (api.weather.gov) for Collinsville (38.676, -90.006). Updated through the day.
Growing snapshot for Collinsville
Last spring frost
Apr 8
First fall frost
Oct 26
Growing season
200 days
Hardiness zone
7a
More local growing data for Collinsville: nearby ZIP 62234 weather · frost dates · planting calendar · Illinois frost dates
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Climate data from the nearest NOAA station, Cahokia St Louis Ap, Il (12.2 mi from Collinsville). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 18, 2026.