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.

Fair

78°F

26°C

Humidity 33%
Wind Speed W 7 mph
Barometer 29.96 in (1014.3 mb)
Dewpoint 47°F (8°C)
Visibility 10.00 mi
Heat Index78°F (26°C)
Last update 12 May 7:53 pm CDT
Extended Forecast for

Swansea IL

  • Tonight

    Tonight: A slight chance of showers and thunderstorms between 11pm and 1am. Mostly cloudy, then gradual clearing toward daybreak, with a low around 58. Southwest wind around 8 mph becoming northwest after midnight. Chance of precipitation is 20%.

    Low: 58 °F

    Slight Chance
    T-storms

  • Wednesday

    Wednesday: Sunny, with a high near 75. Northwest wind 7 to 13 mph, with gusts as high as 21 mph.

    High: 75 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Clear, with a low around 49. North wind 5 to 8 mph becoming calm in the evening.

    Low: 49 °F

    Clear

  • Thursday

    Thursday: Sunny, with a high near 75. Calm wind becoming southeast 5 to 7 mph in the afternoon.

    High: 75 °F

    Sunny

  • Thursday Night

    Thursday Night: A chance of showers between 1am and 4am, then a chance of showers and thunderstorms after 4am. Partly cloudy, with a low around 57. Southeast wind 8 to 13 mph, with gusts as high as 22 mph. Chance of precipitation is 50%.

    Low: 57 °F

    Partly Cloudy
    then Chance
    Showers

  • Friday

    Friday: A 50 percent chance of showers and thunderstorms before 1pm. Mostly sunny, with a high near 88.

    High: 88 °F

    Chance
    T-storms then
    Chance
    Showers

  • Friday Night

    Friday Night: A 30 percent chance of showers and thunderstorms, mainly before 1am. Partly cloudy, with a low around 67.

    Low: 67 °F

    Chance
    T-storms

  • Saturday

    Saturday: A 40 percent chance of showers and thunderstorms. Mostly sunny, with a high near 89.

    High: 89 °F

    Chance
    T-storms

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms before 1am, then a slight chance of showers. Partly cloudy, with a low around 67. Chance of precipitation is 30%.

    Low: 67 °F

    Chance
    T-storms

Detailed Forecast

Tonight
A slight chance of showers and thunderstorms between 11pm and 1am. Mostly cloudy, then gradual clearing toward daybreak, with a low around 58. Southwest wind around 8 mph becoming northwest after midnight. Chance of precipitation is 20%.
Wednesday
Sunny, with a high near 75. Northwest wind 7 to 13 mph, with gusts as high as 21 mph.
Wednesday Night
Clear, with a low around 49. North wind 5 to 8 mph becoming calm in the evening.
Thursday
Sunny, with a high near 75. Calm wind becoming southeast 5 to 7 mph in the afternoon.
Thursday Night
A chance of showers between 1am and 4am, then a chance of showers and thunderstorms after 4am. Partly cloudy, with a low around 57. Southeast wind 8 to 13 mph, with gusts as high as 22 mph. Chance of precipitation is 50%.
Friday
A 50 percent chance of showers and thunderstorms before 1pm. Mostly sunny, with a high near 88.
Friday Night
A 30 percent chance of showers and thunderstorms, mainly before 1am. Partly cloudy, with a low around 67.
Saturday
A 40 percent chance of showers and thunderstorms. Mostly sunny, with a high near 89.
Saturday Night
A chance of showers and thunderstorms before 1am, then a slight chance of showers. Partly cloudy, with a low around 67. Chance of precipitation is 30%.
Sunday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 89.
Sunday Night
A 30 percent chance of showers and thunderstorms. Partly cloudy, with a low around 72.
Monday
Showers and thunderstorms likely. Partly sunny, with a high near 91. Chance of precipitation is 60%.
Monday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 69. Chance of precipitation is 70%.
Tuesday
Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 85. Chance of precipitation is 70%.
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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:
6:06 pm CDT May 12, 2026
Forecast Valid:
8pm CDT May 12, 2026-6pm CDT May 19, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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