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

74°F

23°C

Humidity 94%
Wind Speed Calm
Barometer 29.92 in (1012.5 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Last update 16 Jul 1:53 am CDT
Extended Forecast for

O'Fallon IL

  • Overnight

    Overnight: Partly cloudy, with a low around 72. Southwest wind around 5 mph.

    Low: 72 °F

    Partly Cloudy

  • Wednesday

    Wednesday: A 30 percent chance of showers and thunderstorms, mainly after 4pm. Mostly sunny, with a high near 93. Heat index values as high as 106. Southwest wind 5 to 8 mph.

    High: 93 °F

    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms before 4am, then a slight chance of showers. Partly cloudy, with a low around 75. Southwest wind 5 to 7 mph. Chance of precipitation is 30%.

    Low: 75 °F

    Chance
    T-storms

  • Thursday

    Thursday: A slight chance of showers, then a chance of showers and thunderstorms after 7am. Mostly sunny, with a high near 91. West wind 6 to 8 mph becoming northwest in the afternoon. Chance of precipitation is 50%.

    High: 91 °F

    Slight Chance
    T-storms then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 72. North wind around 6 mph becoming calm in the evening.

    Low: 72 °F

    Chance
    T-storms

  • Friday

    Friday: A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 85.

    High: 85 °F

    Chance
    T-storms

  • Friday Night

    Friday Night: A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 73.

    Low: 73 °F

    Slight Chance
    T-storms

  • Saturday

    Saturday: A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 90.

    High: 90 °F

    Chance
    T-storms

  • Saturday Night

    Saturday Night: A 30 percent chance of showers and thunderstorms. Partly cloudy, with a low around 75.

    Low: 75 °F

    Chance
    T-storms

Detailed Forecast

Overnight
Partly cloudy, with a low around 72. Southwest wind around 5 mph.
Wednesday
A 30 percent chance of showers and thunderstorms, mainly after 4pm. Mostly sunny, with a high near 93. Heat index values as high as 106. Southwest wind 5 to 8 mph.
Wednesday Night
A chance of showers and thunderstorms before 4am, then a slight chance of showers. Partly cloudy, with a low around 75. Southwest wind 5 to 7 mph. Chance of precipitation is 30%.
Thursday
A slight chance of showers, then a chance of showers and thunderstorms after 7am. Mostly sunny, with a high near 91. West wind 6 to 8 mph becoming northwest in the afternoon. Chance of precipitation is 50%.
Thursday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 72. North wind around 6 mph becoming calm in the evening.
Friday
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 85.
Friday Night
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 73.
Saturday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 90.
Saturday Night
A 30 percent chance of showers and thunderstorms. Partly cloudy, with a low around 75.
Sunday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 93.
Sunday Night
A 30 percent chance of showers and thunderstorms. Partly cloudy, with a low around 75.
Monday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 91.
Monday Night
A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 76.
Tuesday
Sunny, with a high near 94.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
O'Fallon IL
 38.59°N 89.92°W (Elev. 551 ft)
Last Update:
10:07 pm CDT Jul 15, 2025
Forecast Valid:
2am CDT Jul 16, 2025-6pm CDT Jul 22, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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