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

80°F

27°C

Humidity 74%
Wind Speed SW 5 mph
Barometer 29.94 in (1013.5 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 13 Oct 11:53 pm CDT
Extended Forecast for

Swansea IL

  • Overnight

    Overnight: Showers and thunderstorms likely, mainly after 5am. Increasing clouds, with a low around 72. Southwest wind around 6 mph becoming west. Chance of precipitation is 60%.

    Low: 72 °F

    T-storms
    Likely

  • Wednesday

    Wednesday: Showers and thunderstorms before 11am, then showers likely and possibly a thunderstorm between 11am and 1pm, then a chance of showers and thunderstorms after 1pm. High near 79. Northwest wind around 6 mph becoming light and variable. Chance of precipitation is 90%.

    High: 79 °F

    T-storms then
    Showers
    Likely

  • Wednesday Night

    Wednesday Night: A slight chance of showers, then a chance of showers and thunderstorms after 10pm. Mostly cloudy, with a low around 67. North wind around 6 mph becoming east after midnight. Chance of precipitation is 30%.

    Low: 67 °F

    Chance
    T-storms

  • Thursday

    Thursday: Showers likely and possibly a thunderstorm before noon, then a chance of showers and thunderstorms after noon. Cloudy through mid morning, then gradual clearing, with a high near 84. East wind 6 to 9 mph becoming southwest in the afternoon. Chance of precipitation is 60%.

    High: 84 °F

    Showers
    Likely then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm before 7pm, then a chance of showers and thunderstorms between 7pm and 1am, then a slight chance of showers after 1am. Mostly cloudy, with a low around 52. Northwest wind 8 to 18 mph, with gusts as high as 28 mph. Chance of precipitation is 60%.

    Low: 52 °F

    Showers
    Likely

  • Friday

    Friday: Mostly sunny, with a high near 61. Breezy.

    High: 61 °F

    Mostly Sunny
    and Breezy

  • Friday Night

    Friday Night: Mostly clear, with a low around 38.

    Low: 38 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 62.

    High: 62 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 38.

    Low: 38 °F

    Clear

Detailed Forecast

Overnight
Showers and thunderstorms likely, mainly after 5am. Increasing clouds, with a low around 72. Southwest wind around 6 mph becoming west. Chance of precipitation is 60%.
Wednesday
Showers and thunderstorms before 11am, then showers likely and possibly a thunderstorm between 11am and 1pm, then a chance of showers and thunderstorms after 1pm. High near 79. Northwest wind around 6 mph becoming light and variable. Chance of precipitation is 90%.
Wednesday Night
A slight chance of showers, then a chance of showers and thunderstorms after 10pm. Mostly cloudy, with a low around 67. North wind around 6 mph becoming east after midnight. Chance of precipitation is 30%.
Thursday
Showers likely and possibly a thunderstorm before noon, then a chance of showers and thunderstorms after noon. Cloudy through mid morning, then gradual clearing, with a high near 84. East wind 6 to 9 mph becoming southwest in the afternoon. Chance of precipitation is 60%.
Thursday Night
Showers likely and possibly a thunderstorm before 7pm, then a chance of showers and thunderstorms between 7pm and 1am, then a slight chance of showers after 1am. Mostly cloudy, with a low around 52. Northwest wind 8 to 18 mph, with gusts as high as 28 mph. Chance of precipitation is 60%.
Friday
Mostly sunny, with a high near 61. Breezy.
Friday Night
Mostly clear, with a low around 38.
Saturday
Sunny, with a high near 62.
Saturday Night
Clear, with a low around 38.
Sunday
Sunny, with a high near 70.
Sunday Night
Partly cloudy, with a low around 47.
Monday
Mostly sunny, with a high near 74.
Monday Night
Partly cloudy, with a low around 50.
Tuesday
Mostly sunny, with a high near 79.
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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:
11:11 pm CDT Oct 13, 2026
Forecast Valid:
12am CDT Oct 14, 2026-6pm CDT Oct 20, 2026
 
Forecast Discussion
 
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Additional Resources

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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