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

5°F

-15°C

Humidity 36%
Wind Speed N 14 mph
Barometer 30.72 in (1041.2 mb)
Dewpoint -16°F (-27°C)
Visibility 10.00 mi
Wind Chill-12°F (-24°C)
Last update 23 Jan 8:53 pm CST
Extended Forecast for

O'Fallon IL

Cold Weather Advisory until January 24, 12:00pm
Winter Storm Warning January 24, 12:00am until January 25, 06:00pm
Click here for hazard details and duration
Cold Weather Advisory
Winter Storm Warning
  •  
    Cold Weather Advisory until January 24, 12:00pm

    NOW until 12:00pm Sat

    Cold Weather Advisory

  • Tonight

    Low: 4 °F

    Increasing
    Clouds

  • Saturday

    Saturday: Snow, mainly after noon. High near 12. Wind chill values as low as -10. Northeast wind 10 to 13 mph, with gusts as high as 20 mph. Chance of precipitation is 90%. New snow accumulation of 1 to 2 inches possible.

    High: 12 °F

    Chance Snow
    then Snow

  • Saturday Night

    Saturday Night: Snow. The snow could be heavy at times. Low around 10. Northeast wind 9 to 11 mph, with gusts as high as 20 mph. Chance of precipitation is 100%. New snow accumulation of 3 to 5 inches possible.

    Low: 10 °F

    Snow Likely
    then Heavy
    Snow

  • Sunday

    Sunday: Snow. High near 16. North wind 10 to 14 mph, with gusts as high as 23 mph. Chance of precipitation is 90%. New snow accumulation of 2 to 4 inches possible.

    High: 16 °F

    Snow then
    Snow Likely

  • Sunday Night

    Sunday Night: A 20 percent chance of snow before midnight. Mostly cloudy, with a low around 0. Northwest wind 10 to 13 mph, with gusts as high as 20 mph.

    Low: 0 °F

    Slight Chance
    Snow then
    Partly Cloudy

  • Monday

    Monday: Mostly sunny and cold, with a high near 15.

    High: 15 °F

    Cold

  • Monday Night

    Monday Night: Mostly clear, with a low around 3.

    Low: 3 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 31.

    High: 31 °F

    Sunny

Detailed Forecast

Tonight
Increasing clouds, with a low around 4. Wind chill values as low as -10. Northeast wind 11 to 13 mph, with gusts as high as 21 mph.
Saturday
Snow, mainly after noon. High near 12. Wind chill values as low as -10. Northeast wind 10 to 13 mph, with gusts as high as 20 mph. Chance of precipitation is 90%. New snow accumulation of 1 to 2 inches possible.
Saturday Night
Snow. The snow could be heavy at times. Low around 10. Northeast wind 9 to 11 mph, with gusts as high as 20 mph. Chance of precipitation is 100%. New snow accumulation of 3 to 5 inches possible.
Sunday
Snow. High near 16. North wind 10 to 14 mph, with gusts as high as 23 mph. Chance of precipitation is 90%. New snow accumulation of 2 to 4 inches possible.
Sunday Night
A 20 percent chance of snow before midnight. Mostly cloudy, with a low around 0. Northwest wind 10 to 13 mph, with gusts as high as 20 mph.
Monday
Mostly sunny and cold, with a high near 15.
Monday Night
Mostly clear, with a low around 3.
Tuesday
Sunny, with a high near 31.
Tuesday Night
Partly cloudy, with a low around 5.
Wednesday
Partly sunny, with a high near 24.
Wednesday Night
Partly cloudy, with a low around 5.
Thursday
Mostly sunny and cold, with a high near 19.
Thursday Night
Partly cloudy, with a low around 4.
Friday
Mostly sunny, with a high near 21.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
O'Fallon IL
 38.59°N 89.95°W (Elev. 545 ft)
Last Update:
8:21 pm CST Jan 23, 2026
Forecast Valid:
9pm CST Jan 23, 2026-6pm CST Jan 30, 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