Dupo, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Dupo, a village in St. Clair County, Illinois.
Tonight
74°F
Partly Cloudy
Partly cloudy, with a low around 74. South wind around 6 mph.
7-day forecast for Dupo
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 74°F | Partly Cloudy | 6 mph S | 12% |
| Saturday | 99°F | Mostly Sunny | 3 to 7 mph SW | 6% |
| Saturday Night | 74°F | Partly Cloudy | 6 mph S | 1% |
| Sunday | 95°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 6 mph W | 17% |
| Sunday Night | 68°F | Slight Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 7 mph N | 56% |
| Monday | 81°F | Showers And Thunderstorms Likely | 8 mph N | 69% |
| Monday Night | 61°F | Showers And Thunderstorms Likely then Slight Chance Showers And Thunderstorms | 9 mph N | 69% |
| Tuesday | 72°F | Slight Chance Rain Showers then Mostly Cloudy | 10 mph N | 24% |
| Tuesday Night | 56°F | Mostly Cloudy | 6 to 10 mph N | 6% |
| Wednesday | 75°F | Mostly Sunny | 8 mph N | 2% |
| Wednesday Night | 56°F | Partly Cloudy | 3 to 7 mph N | 2% |
| Thursday | 75°F | Mostly Sunny | 3 to 7 mph N | 3% |
| Thursday Night | 58°F | Partly Cloudy | 6 mph NE | 3% |
| Friday | 77°F | Mostly Sunny | 3 to 7 mph N | 6% |
Forecast source: National Weather Service (api.weather.gov) for Dupo (38.516, -90.218). Updated through the day.
Growing snapshot for Dupo
Last spring frost
Apr 6
First fall frost
Oct 27
Growing season
203 days
Hardiness zone
7a
More local growing data for Dupo: nearby ZIP 62240 weather · frost dates · planting calendar · Illinois frost dates
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Climate data from the nearest NOAA station, Cahokia, Il (4.6 mi from Dupo). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.