National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

St. Louis Downtown Airport (KCPS)

Lat: 38.56°NLon: 90.15°WElev: 410ft.

Fair

78°F

26°C

Humidity 87%
Wind Speed S 6 mph
Barometer 29.93 in (1013.0 mb)
Dewpoint 74°F (23°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 21 Jun 2:53 am CDT
Extended Forecast for

Collinsville IL

Extreme Heat Warning June 21, 12:00pm until June 24, 09:00pm
Click here for hazard details and duration
Extreme Heat Warning

  • Overnight

    Overnight: Mostly clear, with a low around 76. South wind around 9 mph.

    Low: 76 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 96. Heat index values as high as 107. South wind 10 to 15 mph, with gusts as high as 22 mph.

    High: 96 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 77. South wind 7 to 13 mph, with gusts as high as 20 mph.

    Low: 77 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 96. Heat index values as high as 104. South wind 7 to 11 mph.

    High: 96 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 76. South wind 6 to 10 mph.

    Low: 76 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 96.

    High: 96 °F

    Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 76.

    Low: 76 °F

    Partly Cloudy

  • Tuesday

    Tuesday: A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 94.

    High: 94 °F

    Slight Chance
    T-storms

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 75.

    Low: 75 °F

    Partly Cloudy

Detailed Forecast

Overnight
Mostly clear, with a low around 76. South wind around 9 mph.
Saturday
Sunny, with a high near 96. Heat index values as high as 107. South wind 10 to 15 mph, with gusts as high as 22 mph.
Saturday Night
Clear, with a low around 77. South wind 7 to 13 mph, with gusts as high as 20 mph.
Sunday
Sunny, with a high near 96. Heat index values as high as 104. South wind 7 to 11 mph.
Sunday Night
Mostly clear, with a low around 76. South wind 6 to 10 mph.
Monday
Sunny, with a high near 96.
Monday Night
Partly cloudy, with a low around 76.
Tuesday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 94.
Tuesday Night
Partly cloudy, with a low around 75.
Wednesday
A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 94.
Wednesday Night
Mostly clear, with a low around 76.
Thursday
A 20 percent chance of showers and thunderstorms. Sunny, with a high near 94.
Thursday Night
A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 75.
Friday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 91.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Collinsville IL
 38.68°N 89.97°W (Elev. 502 ft)
Last Update:
3:21 am CDT Jun 21, 2025
Forecast Valid:
3am CDT Jun 21, 2025-6pm CDT Jun 27, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation