Dupo, IL Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Dupo, a village in St. Clair County, Illinois.

This Afternoon

73°F

Rain

Rain and a slight chance of thunderstorms. Cloudy. High near 73, with temperatures falling to around 67 in the afternoon. South wind around 20 mph, with gusts as high as 30 mph. Chance of precipitation is 100%.

7-day forecast for Dupo

When	Temp	Forecast	Wind	Precip
This Afternoon	73°F	Rain	20 mph S	96%
Tonight	53°F	Rain	8 to 17 mph S	96%
Wednesday	64°F	Mostly Cloudy	7 to 13 mph W	5%
Wednesday Night	45°F	Partly Cloudy	5 mph SW	0%
Thursday	67°F	Sunny	5 to 9 mph W	1%
Thursday Night	46°F	Mostly Cloudy	5 mph NW	10%
Friday	59°F	Partly Sunny	5 to 9 mph NW	5%
Friday Night	41°F	Partly Cloudy	2 to 6 mph N	1%
Saturday	57°F	Partly Sunny	3 mph NW	0%
Saturday Night	38°F	Partly Cloudy	2 mph NW	0%
Sunday	63°F	Sunny	2 to 6 mph W	8%
Sunday Night	38°F	Mostly Clear	5 mph W	5%
Monday	67°F	Sunny	2 to 6 mph SW	2%
Monday Night	42°F	Mostly Clear	3 mph SW	1%

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

More local growing data for Dupo: nearby ZIP 62240 weather · frost dates · planting calendar · Illinois frost dates

Nearby towns & communities

Belleville Brooklyn Cahokia Heights Caseyville Darmstadt East St. Louis Fairmont City Fairview Heights Fayetteville Floraville Freeburg Lebanon Lenzburg Marissa Mascoutah Millstadt New Athens O'Fallon Paderborn Rentchler Sauget Scott AFB Shiloh Smithton St. Libory Summerfield Swansea Washington Park

All Illinois locations ›

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 Nov 3, 2026.