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

53°F

12°C

Humidity 48%
Wind Speed S 10 G 18 mph
Barometer 29.79 in (1008.8 mb)
Dewpoint 34°F (1°C)
Visibility 10.00 mi
Wind Chill50°F (10°C)
Last update 9 Dec 1:53 pm CST
Extended Forecast for

O'Fallon IL

Wind Advisory December 10, 03:00am until December 10, 12:00pm
Click here for hazard details and duration
Wind Advisory

  • This Afternoon

    This Afternoon: Partly sunny, with a high near 54. South wind 13 to 15 mph, with gusts as high as 23 mph.

    High: 54 °F

    Partly Sunny

  • Tonight

    Tonight: A slight chance of rain between 1am and 4am. Mostly cloudy, with a steady temperature around 44. South wind 15 to 17 mph becoming west after midnight. Winds could gust as high as 28 mph. Chance of precipitation is 20%.

    Low: 44 °F

    Mostly Cloudy
    then Slight
    Chance Rain

  • Wednesday

    Wednesday: Partly sunny, with a temperature falling to around 35 by 5pm. Breezy, with a northwest wind 15 to 25 mph, with gusts as high as 46 mph.

    High: 42 °F⇓

    Partly Sunny
    and Breezy

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 25. Northwest wind 6 to 11 mph becoming light after midnight.

    Low: 25 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly cloudy, with a high near 38. Calm wind becoming southeast 5 to 7 mph in the morning.

    High: 38 °F

    Mostly Cloudy

  • Thursday Night

    Thursday Night: A 20 percent chance of snow before midnight. Mostly cloudy, with a low around 34.

    Low: 34 °F

    Slight Chance
    Snow then
    Mostly Cloudy

  • Friday

    Friday: Partly sunny, with a high near 42.

    High: 42 °F

    Partly Sunny

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 23.

    Low: 23 °F

    Mostly Cloudy

  • Saturday

    Saturday: Mostly cloudy, with a high near 33.

    High: 33 °F

    Mostly Cloudy

Detailed Forecast

This Afternoon
Partly sunny, with a high near 54. South wind 13 to 15 mph, with gusts as high as 23 mph.
Tonight
A slight chance of rain between 1am and 4am. Mostly cloudy, with a steady temperature around 44. South wind 15 to 17 mph becoming west after midnight. Winds could gust as high as 28 mph. Chance of precipitation is 20%.
Wednesday
Partly sunny, with a temperature falling to around 35 by 5pm. Breezy, with a northwest wind 15 to 25 mph, with gusts as high as 46 mph.
Wednesday Night
Mostly cloudy, with a low around 25. Northwest wind 6 to 11 mph becoming light after midnight.
Thursday
Mostly cloudy, with a high near 38. Calm wind becoming southeast 5 to 7 mph in the morning.
Thursday Night
A 20 percent chance of snow before midnight. Mostly cloudy, with a low around 34.
Friday
Partly sunny, with a high near 42.
Friday Night
Mostly cloudy, with a low around 23.
Saturday
Mostly cloudy, with a high near 33.
Saturday Night
Mostly cloudy, with a low around 10.
Sunday
Sunny, with a high near 23.
Sunday Night
Partly cloudy, with a low around 13.
Monday
Mostly sunny, with a high near 37.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
O'Fallon IL
 38.59°N 89.92°W (Elev. 551 ft)
Last Update:
2:27 pm CST Dec 9, 2025
Forecast Valid:
2pm CST Dec 9, 2025-6pm CST Dec 15, 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