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

St. Louis Downtown Airport (KCPS)

Lat: 38.56°NLon: 90.15°WElev: 410ft.

Fair

59°F

15°C

Humidity 36%
Wind Speed NW 15 mph
Barometer 30.28 in (1025.2 mb)
Dewpoint 32°F (0°C)
Visibility 10.00 mi
Last update 5 Apr 4:53 pm CDT
Extended Forecast for

Collinsville IL

  • Tonight

    Tonight: Clear, with a low around 40. Northwest wind 5 to 10 mph becoming light and variable.

    Low: 40 °F

    Clear

  • Monday

    Monday: Increasing clouds, with a high near 61. Northwest wind 6 to 11 mph.

    High: 61 °F

    Increasing
    Clouds

  • Monday Night

    Monday Night: A 20 percent chance of showers after 1am. Mostly cloudy, with a low around 39. North wind 8 to 10 mph.

    Low: 39 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Tuesday

    Tuesday: Partly sunny, with a high near 53. East wind around 9 mph.

    High: 53 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 40. East wind around 8 mph.

    Low: 40 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 72.

    High: 72 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 55.

    Low: 55 °F

    Partly Cloudy

  • Thursday

    Thursday: A slight chance of showers, with thunderstorms also possible after 1pm. Mostly sunny, with a high near 72. Chance of precipitation is 20%.

    High: 72 °F

    Slight Chance
    Showers then
    Slight Chance
    T-storms

  • Thursday Night

    Thursday Night: A slight chance of showers and thunderstorms, then a chance of showers after 1am. Mostly cloudy, with a low around 58. Chance of precipitation is 30%.

    Low: 58 °F

    Slight Chance
    T-storms then
    Chance
    Showers

Detailed Forecast

Tonight
Clear, with a low around 40. Northwest wind 5 to 10 mph becoming light and variable.
Monday
Increasing clouds, with a high near 61. Northwest wind 6 to 11 mph.
Monday Night
A 20 percent chance of showers after 1am. Mostly cloudy, with a low around 39. North wind 8 to 10 mph.
Tuesday
Partly sunny, with a high near 53. East wind around 9 mph.
Tuesday Night
Mostly cloudy, with a low around 40. East wind around 8 mph.
Wednesday
Mostly sunny, with a high near 72.
Wednesday Night
Partly cloudy, with a low around 55.
Thursday
A slight chance of showers, with thunderstorms also possible after 1pm. Mostly sunny, with a high near 72. Chance of precipitation is 20%.
Thursday Night
A slight chance of showers and thunderstorms, then a chance of showers after 1am. Mostly cloudy, with a low around 58. Chance of precipitation is 30%.
Friday
A chance of showers, with thunderstorms also possible after 1pm. Partly sunny, with a high near 75. Chance of precipitation is 40%.
Friday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 57.
Saturday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 80.
Saturday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 62.
Sunday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 82.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Collinsville IL
 38.66°N 90°W (Elev. 499 ft)
Last Update:
1:26 pm CDT Apr 5, 2026
Forecast Valid:
5pm CDT Apr 5, 2026-6pm CDT Apr 12, 2026
 
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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