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

68°F

20°C

Humidity 96%
Wind Speed Calm
Barometer 30.03 in (1016.7 mb)
Dewpoint 67°F (19°C)
Visibility 8.00 mi
Last update 14 Oct 9:53 pm CDT
Extended Forecast for

Herculaneum MO

  • Tonight

    Tonight: Scattered showers, with thunderstorms also possible after 4am. Mostly cloudy, with a low around 67. Calm wind. Chance of precipitation is 40%.

    Low: 67 °F

    Cloudy then
    Scattered
    T-storms

  • Thursday

    Thursday: Showers likely and possibly a thunderstorm before 11am, then a chance of showers and thunderstorms after 11am. Cloudy, then gradually becoming mostly sunny, with a high near 82. Calm wind becoming southwest 5 to 9 mph in the morning. Chance of precipitation is 70%.

    High: 82 °F

    Showers
    Likely then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: Showers and thunderstorms likely before 2am, then a slight chance of showers between 2am and 3am. Increasing clouds, with a low around 44. Southwest wind 8 to 11 mph becoming northwest after midnight. Winds could gust as high as 23 mph. Chance of precipitation is 70%.

    Low: 44 °F

    Showers
    Likely

  • Friday

    Friday: Partly sunny, with a high near 57. Northwest wind 13 to 15 mph, with gusts as high as 26 mph.

    High: 57 °F

    Partly Sunny

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 38. Northwest wind 6 to 13 mph, with gusts as high as 24 mph.

    Low: 38 °F

    Mostly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 62.

    High: 62 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 35.

    Low: 35 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 69.

    High: 69 °F

    Sunny

  • Sunday Night

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

    Low: 38 °F

    Mostly Clear

Detailed Forecast

Tonight
Scattered showers, with thunderstorms also possible after 4am. Mostly cloudy, with a low around 67. Calm wind. Chance of precipitation is 40%.
Thursday
Showers likely and possibly a thunderstorm before 11am, then a chance of showers and thunderstorms after 11am. Cloudy, then gradually becoming mostly sunny, with a high near 82. Calm wind becoming southwest 5 to 9 mph in the morning. Chance of precipitation is 70%.
Thursday Night
Showers and thunderstorms likely before 2am, then a slight chance of showers between 2am and 3am. Increasing clouds, with a low around 44. Southwest wind 8 to 11 mph becoming northwest after midnight. Winds could gust as high as 23 mph. Chance of precipitation is 70%.
Friday
Partly sunny, with a high near 57. Northwest wind 13 to 15 mph, with gusts as high as 26 mph.
Friday Night
Mostly cloudy, with a low around 38. Northwest wind 6 to 13 mph, with gusts as high as 24 mph.
Saturday
Sunny, with a high near 62.
Saturday Night
Clear, with a low around 35.
Sunday
Sunny, with a high near 69.
Sunday Night
Mostly clear, with a low around 38.
Monday
Mostly sunny, with a high near 73.
Monday Night
Partly cloudy, with a low around 42.
Tuesday
Mostly sunny, with a high near 77.
Tuesday Night
Mostly clear, with a low around 47.
Wednesday
Sunny, with a high near 80.
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ABOUT THIS FORECAST

 
Point Forecast:
Herculaneum MO
 38.27°N 90.39°W (Elev. 456 ft)
Last Update:
10:21 pm CDT Oct 14, 2026
Forecast Valid:
10pm CDT Oct 14, 2026-6pm CDT Oct 21, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation