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.

Rain

53°F

12°C

Humidity 96%
Wind Speed E 7 mph
Barometer 29.98 in (1015.1 mb)
Dewpoint 52°F (11°C)
Visibility 7.00 mi
Wind Chill51°F (11°C)
Last update 21 Nov 6:53 am CST
Extended Forecast for

O'Fallon IL

  • Today

    Today: Rain, mainly before 1pm. Patchy fog before 1pm. High near 56. East wind around 7 mph. Chance of precipitation is 100%.

    High: 56 °F

    Rain and
    Patchy Fog
    then Rain
    Likely and
    Patchy Fog

  • Tonight

    Tonight: Rain likely, mainly before 4am. Patchy fog between midnight and 1am. Otherwise, cloudy, with a low around 45. North wind 6 to 8 mph. Chance of precipitation is 60%.

    Low: 45 °F

    Rain Likely
    and Patchy
    Fog

  • Saturday

    Saturday: Sunny, with a high near 57. North wind around 6 mph becoming light and variable in the afternoon.

    High: 57 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 40. Calm wind.

    Low: 40 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 63. Calm wind becoming west around 5 mph.

    High: 63 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 44.

    Low: 44 °F

    Mostly Cloudy

  • Monday

    Monday: Rain likely, mainly after noon. Cloudy, with a high near 59. Chance of precipitation is 70%.

    High: 59 °F

    Chance Rain
    then Rain
    Likely

  • Monday Night

    Monday Night: Rain and possibly a thunderstorm before midnight, then a chance of rain. Low around 51. Chance of precipitation is 80%.

    Low: 51 °F

    Rain then
    Chance Rain

  • Tuesday

    Tuesday: A 20 percent chance of rain before noon. Partly sunny, with a high near 63.

    High: 63 °F

    Slight Chance
    Rain then
    Partly Sunny

Detailed Forecast

Today
Rain, mainly before 1pm. Patchy fog before 1pm. High near 56. East wind around 7 mph. Chance of precipitation is 100%.
Tonight
Rain likely, mainly before 4am. Patchy fog between midnight and 1am. Otherwise, cloudy, with a low around 45. North wind 6 to 8 mph. Chance of precipitation is 60%.
Saturday
Sunny, with a high near 57. North wind around 6 mph becoming light and variable in the afternoon.
Saturday Night
Mostly clear, with a low around 40. Calm wind.
Sunday
Sunny, with a high near 63. Calm wind becoming west around 5 mph.
Sunday Night
Mostly cloudy, with a low around 44.
Monday
Rain likely, mainly after noon. Cloudy, with a high near 59. Chance of precipitation is 70%.
Monday Night
Rain and possibly a thunderstorm before midnight, then a chance of rain. Low around 51. Chance of precipitation is 80%.
Tuesday
A 20 percent chance of rain before noon. Partly sunny, with a high near 63.
Tuesday Night
Mostly cloudy, with a low around 37.
Wednesday
Mostly sunny, with a high near 48.
Wednesday Night
Partly cloudy, with a low around 28.
Thanksgiving Day
Mostly sunny, with a high near 45.
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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:
5:41 am CST Nov 21, 2025
Forecast Valid:
7am CST Nov 21, 2025-6pm CST Nov 27, 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