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

37°F

3°C

Humidity 76%
Wind Speed SW 5 mph
Barometer 29.92 in (1013.4 mb)
Dewpoint 30°F (-1°C)
Visibility 10.00 mi
Wind Chill33°F (1°C)
Last update 6 Dec 3:53 am CST
Extended Forecast for

Swansea IL

  • Today

    Today: Mostly sunny, with a high near 43. Calm wind becoming east around 6 mph in the afternoon.

    High: 43 °F

    Mostly Sunny

  • Tonight

    Tonight: A 20 percent chance of rain between 3am and 4am. Cloudy, with a low around 35. Southeast wind 6 to 8 mph becoming south after midnight.

    Low: 35 °F

    Mostly Cloudy
    then Slight
    Chance Rain

  • Sunday

    Sunday: Mostly cloudy, with a temperature rising to near 40 by 11am, then falling to around 32 during the remainder of the day. South wind 5 to 11 mph becoming north in the afternoon.

    High: 40 °F⇓

    Mostly Cloudy

  • Sunday Night

    Sunday Night: A 20 percent chance of snow before midnight. Mostly cloudy, with a low around 19. North wind 6 to 10 mph.

    Low: 19 °F

    Slight Chance
    Snow then
    Mostly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 33. North wind around 6 mph becoming calm in the morning.

    High: 33 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 24.

    Low: 24 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 50.

    High: 50 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 39.

    Low: 39 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Partly sunny, with a high near 46.

    High: 46 °F

    Partly Sunny

Detailed Forecast

Today
Mostly sunny, with a high near 43. Calm wind becoming east around 6 mph in the afternoon.
Tonight
A 20 percent chance of rain between 3am and 4am. Cloudy, with a low around 35. Southeast wind 6 to 8 mph becoming south after midnight.
Sunday
Mostly cloudy, with a temperature rising to near 40 by 11am, then falling to around 32 during the remainder of the day. South wind 5 to 11 mph becoming north in the afternoon.
Sunday Night
A 20 percent chance of snow before midnight. Mostly cloudy, with a low around 19. North wind 6 to 10 mph.
Monday
Mostly sunny, with a high near 33. North wind around 6 mph becoming calm in the morning.
Monday Night
Partly cloudy, with a low around 24.
Tuesday
Mostly sunny, with a high near 50.
Tuesday Night
Mostly cloudy, with a low around 39.
Wednesday
Partly sunny, with a high near 46.
Wednesday Night
Mostly cloudy, with a low around 27.
Thursday
A slight chance of rain and snow. Mostly cloudy, with a high near 38. Chance of precipitation is 20%.
Thursday Night
Mostly cloudy, with a low around 22.
Friday
Mostly sunny, with a high near 30.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Swansea IL
 38.55°N 89.98°W (Elev. 551 ft)
Last Update:
3:16 am CST Dec 6, 2025
Forecast Valid:
4am CST Dec 6, 2025-6pm CST Dec 12, 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