Belleville, IL Weather & Growing Conditions
Today
98°F
Partly Sunny
Partly sunny, with a high near 98. Heat index values as high as 102. Southwest wind around 8 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 98°F | Partly Sunny | 8 mph SW | 2% |
| Tonight | 74°F | Partly Cloudy | 6 mph SW | 4% |
| Sunday | 94°F | Chance Rain Showers then Slight Chance Showers And Thunderstorms | 3 to 7 mph W | 25% |
| Sunday Night | 68°F | Showers And Thunderstorms Likely | 6 to 9 mph NE | 59% |
| Monday | 79°F | Showers And Thunderstorms Likely | 7 to 12 mph NE | 64% |
| Monday Night | 60°F | Showers And Thunderstorms Likely | 7 to 12 mph N | 55% |
| Tuesday | 72°F | Slight Chance Rain Showers then Partly Sunny | 12 mph N | 20% |
| Tuesday Night | 55°F | Mostly Cloudy | 6 to 12 mph N | 5% |
| Wednesday | 74°F | Mostly Sunny | 10 mph N | 1% |
| Wednesday Night | 56°F | Partly Cloudy | 3 to 9 mph N | 0% |
| Thursday | 77°F | Mostly Sunny | 5 to 8 mph N | 1% |
| Thursday Night | 58°F | Partly Cloudy | 3 to 7 mph NE | 4% |
| Friday | 78°F | Partly Sunny | 3 to 8 mph NE | 6% |
| Friday Night | 58°F | Partly Cloudy | 3 to 7 mph NE | 6% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Belleville, IL
Last spring frost
Apr 8
First fall frost
Oct 26
Growing season
200 days
Hardiness zone
7a
Explore more for Belleville, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Cahokia St Louis Ap, Il (5.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.