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

78°F

26°C

Humidity 43%
Wind Speed SE 5 mph
Barometer 29.91 in (1012.8 mb)
Dewpoint 54°F (12°C)
Visibility 10.00 mi
Heat Index79°F (26°C)
Last update 29 Sep 5:53 pm CDT
Extended Forecast for

Belleville IL

  • Tonight

    Tonight: Mostly cloudy, with a low around 67. South wind around 6 mph.

    Low: 67 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Cloudy, then gradually becoming mostly sunny, with a high near 91. South wind 5 to 9 mph.

    High: 91 °F

    Decreasing
    Clouds

  • Wednesday Night

    Wednesday Night: Cloudy, then gradually becoming partly cloudy, with a low around 72. South wind 7 to 9 mph.

    Low: 72 °F

    Decreasing
    Clouds

  • Thursday

    Thursday: A chance of showers between 1pm and 4pm, then a chance of showers and thunderstorms after 4pm. Increasing clouds, with a high near 89. South wind 8 to 13 mph, with gusts as high as 20 mph. Chance of precipitation is 30%.

    High: 89 °F

    Partly Sunny
    then Chance
    Showers

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 1am, then showers between 1am and 4am, then showers and possibly a thunderstorm after 4am. Low around 68. Southwest wind 5 to 7 mph. Chance of precipitation is 80%.

    Low: 68 °F

    Chance
    Showers then
    Showers

  • Friday

    Friday: Showers and possibly a thunderstorm before 1pm, then a chance of showers. High near 73. Chance of precipitation is 80%.

    High: 73 °F

    Showers

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 57.

    Low: 57 °F

    Mostly Cloudy

  • Saturday

    Saturday: A 30 percent chance of showers after 1pm. Partly sunny, with a high near 69.

    High: 69 °F

    Partly Sunny
    then Chance
    Showers

  • Saturday Night

    Saturday Night: A 20 percent chance of showers before 1am. Mostly cloudy, with a low around 55.

    Low: 55 °F

    Slight Chance
    Showers

Detailed Forecast

Tonight
Mostly cloudy, with a low around 67. South wind around 6 mph.
Wednesday
Cloudy, then gradually becoming mostly sunny, with a high near 91. South wind 5 to 9 mph.
Wednesday Night
Cloudy, then gradually becoming partly cloudy, with a low around 72. South wind 7 to 9 mph.
Thursday
A chance of showers between 1pm and 4pm, then a chance of showers and thunderstorms after 4pm. Increasing clouds, with a high near 89. South wind 8 to 13 mph, with gusts as high as 20 mph. Chance of precipitation is 30%.
Thursday Night
A chance of showers and thunderstorms before 1am, then showers between 1am and 4am, then showers and possibly a thunderstorm after 4am. Low around 68. Southwest wind 5 to 7 mph. Chance of precipitation is 80%.
Friday
Showers and possibly a thunderstorm before 1pm, then a chance of showers. High near 73. Chance of precipitation is 80%.
Friday Night
Mostly cloudy, with a low around 57.
Saturday
A 30 percent chance of showers after 1pm. Partly sunny, with a high near 69.
Saturday Night
A 20 percent chance of showers before 1am. Mostly cloudy, with a low around 55.
Sunday
Mostly sunny, with a high near 71.
Sunday Night
Mostly clear, with a low around 52.
Monday
Sunny, with a high near 69.
Monday Night
Mostly clear, with a low around 48.
Tuesday
Sunny, with a high near 70.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Belleville IL
 38.52°N 90.01°W (Elev. 535 ft)
Last Update:
6:16 pm CDT Sep 29, 2026
Forecast Valid:
6pm CDT Sep 29, 2026-6pm CDT Oct 6, 2026
 
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