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

67°F

19°C

Humidity 59%
Wind Speed Calm
Barometer 30.00 in (1015.5 mb)
Dewpoint 52°F (11°C)
Visibility 10.00 mi
Last update 28 Sep 6:53 pm CDT
Extended Forecast for

Swansea IL

  • Tonight

    Tonight: Clear, with a low around 52. Light east wind.

    Low: 52 °F

    Clear

  • Tuesday

    Tuesday: Sunny, with a high near 83. Calm wind becoming south around 6 mph in the afternoon.

    High: 83 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 63. Southeast wind around 5 mph.

    Low: 63 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 89. South wind 6 to 11 mph.

    High: 89 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 71. South wind around 9 mph.

    Low: 71 °F

    Mostly Cloudy

  • Thursday

    Thursday: A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 86. Chance of precipitation is 60%.

    High: 86 °F

    Chance
    Showers then
    Showers
    Likely

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 66. Chance of precipitation is 70%.

    Low: 66 °F

    Showers
    Likely

  • Friday

    Friday: Showers likely and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 72. Chance of precipitation is 60%.

    High: 72 °F

    Showers
    Likely

  • Friday Night

    Friday Night: A 40 percent chance of showers, mainly after 1am. Mostly cloudy, with a low around 58.

    Low: 58 °F

    Chance
    Showers

Detailed Forecast

Tonight
Clear, with a low around 52. Light east wind.
Tuesday
Sunny, with a high near 83. Calm wind becoming south around 6 mph in the afternoon.
Tuesday Night
Partly cloudy, with a low around 63. Southeast wind around 5 mph.
Wednesday
Mostly sunny, with a high near 89. South wind 6 to 11 mph.
Wednesday Night
Mostly cloudy, with a low around 71. South wind around 9 mph.
Thursday
A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 86. Chance of precipitation is 60%.
Thursday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 66. Chance of precipitation is 70%.
Friday
Showers likely and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 72. Chance of precipitation is 60%.
Friday Night
A 40 percent chance of showers, mainly after 1am. Mostly cloudy, with a low around 58.
Saturday
A 50 percent chance of showers. Mostly cloudy, with a high near 71.
Saturday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 58.
Sunday
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 71.
Sunday Night
Partly cloudy, with a low around 54.
Monday
Mostly sunny, with a high near 68.
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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:
6:01 pm CDT Sep 28, 2026
Forecast Valid:
7pm CDT Sep 28, 2026-6pm CDT Oct 5, 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