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

82°F

28°C

Humidity 44%
Wind Speed NE 3 mph
Barometer 30.07 in (1018.0 mb)
Dewpoint 58°F (14°C)
Visibility 10.00 mi
Heat Index82°F (28°C)
Last update 1 Oct 5:53 pm CDT
Extended Forecast for

Collinsville IL

  • Tonight

    Tonight: Mostly cloudy, with a low around 63. Southeast wind around 5 mph becoming calm in the evening.

    Low: 63 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 89. Calm wind becoming south around 6 mph in the afternoon.

    High: 89 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: A 20 percent chance of showers before 10pm. Partly cloudy, with a low around 66. South wind around 6 mph becoming calm after midnight.

    Low: 66 °F

    Slight Chance
    Showers then
    Mostly Clear

  • Friday

    Friday: Mostly sunny, with a high near 89. Calm wind becoming southwest around 6 mph in the morning.

    High: 89 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 61. South wind around 5 mph becoming calm after midnight.

    Low: 61 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 87.

    High: 87 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 60.

    Low: 60 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 87.

    High: 87 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 64.

    Low: 64 °F

    Mostly Clear

Detailed Forecast

Tonight
Mostly cloudy, with a low around 63. Southeast wind around 5 mph becoming calm in the evening.
Thursday
Mostly sunny, with a high near 89. Calm wind becoming south around 6 mph in the afternoon.
Thursday Night
A 20 percent chance of showers before 10pm. Partly cloudy, with a low around 66. South wind around 6 mph becoming calm after midnight.
Friday
Mostly sunny, with a high near 89. Calm wind becoming southwest around 6 mph in the morning.
Friday Night
Mostly clear, with a low around 61. South wind around 5 mph becoming calm after midnight.
Saturday
Sunny, with a high near 87.
Saturday Night
Clear, with a low around 60.
Sunday
Sunny, with a high near 87.
Sunday Night
Mostly clear, with a low around 64.
Monday
Sunny, with a high near 87.
Monday Night
Mostly clear, with a low around 63.
Tuesday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 83.
Tuesday Night
A 20 percent chance of showers. Partly cloudy, with a low around 59.
Wednesday
Sunny, with a high near 77.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Collinsville IL
 38.68°N 90°W (Elev. 499 ft)
Last Update:
4:16 pm CDT Oct 1, 2025
Forecast Valid:
6pm CDT Oct 1, 2025-6pm CDT Oct 8, 2025
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation