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

64°F

18°C

Humidity 87%
Wind Speed S 3 mph
Barometer 29.96 in (1014.3 mb)
Dewpoint 60°F (16°C)
Visibility 10.00 mi
Last update 12 Oct 1:53 am CDT
Extended Forecast for

4 Miles SE Swansea IL

  • Overnight

    Overnight: Mostly clear, with a low around 61. Southwest wind around 6 mph.

    Low: 61 °F

    Mostly Clear

  • Columbus Day

    Columbus Day: Sunny, with a high near 93. Southwest wind 6 to 13 mph.

    High: 93 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 68. South wind 7 to 9 mph.

    Low: 68 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 95. Heat index values as high as 102. Southwest wind 6 to 9 mph.

    High: 95 °F

    Sunny

  • Tuesday Night

    Tuesday Night: A 40 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 72. South wind 5 to 9 mph.

    Low: 72 °F

    Mostly Clear
    then Chance
    T-storms

  • Wednesday

    Wednesday: Showers and possibly a thunderstorm before 10am, then showers between 10am and 1pm, then showers and possibly a thunderstorm after 1pm. High near 83. Chance of precipitation is 90%.

    High: 83 °F

    Showers

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 1am, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 66. Chance of precipitation is 60%.

    Low: 66 °F

    Showers
    Likely

  • Thursday

    Thursday: Showers and possibly a thunderstorm. High near 82. Chance of precipitation is 80%.

    High: 82 °F

    Showers

  • Thursday Night

    Thursday Night: A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 54.

    Low: 54 °F

    Chance
    Showers

Detailed Forecast

Overnight
Mostly clear, with a low around 61. Southwest wind around 6 mph.
Columbus Day
Sunny, with a high near 93. Southwest wind 6 to 13 mph.
Monday Night
Mostly clear, with a low around 68. South wind 7 to 9 mph.
Tuesday
Sunny, with a high near 95. Heat index values as high as 102. Southwest wind 6 to 9 mph.
Tuesday Night
A 40 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 72. South wind 5 to 9 mph.
Wednesday
Showers and possibly a thunderstorm before 10am, then showers between 10am and 1pm, then showers and possibly a thunderstorm after 1pm. High near 83. Chance of precipitation is 90%.
Wednesday Night
A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 1am, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 66. Chance of precipitation is 60%.
Thursday
Showers and possibly a thunderstorm. High near 82. Chance of precipitation is 80%.
Thursday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 54.
Friday
Mostly sunny, with a high near 64. Breezy.
Friday Night
Mostly clear, with a low around 39.
Saturday
Sunny, with a high near 62.
Saturday Night
Clear, with a low around 37.
Sunday
Sunny, with a high near 70.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
4 Miles SE Swansea IL
 38.5°N 89.93°W (Elev. 499 ft)
Last Update:
1:41 am CDT Oct 12, 2026
Forecast Valid:
2am CDT Oct 12, 2026-6pm CDT Oct 18, 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