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.

Overcast

45°F

7°C

Humidity 77%
Wind Speed NW 20 G 29 mph
Barometer 30.02 in (1016.5 mb)
Dewpoint 38°F (3°C)
Visibility 10.00 mi
Wind Chill37°F (3°C)
Last update 11 Mar 3:53 pm CDT
Extended Forecast for

Herculaneum MO

  • This Afternoon

    This Afternoon: A 20 percent chance of showers. Cloudy, with a steady temperature around 47. Northwest wind around 15 mph, with gusts as high as 29 mph.

    High: 47 °F

    Slight Chance
    Showers

  • Tonight

    Tonight: Mostly cloudy during the early evening, then gradual clearing, with a low around 30. Northwest wind 8 to 13 mph becoming light after midnight. Winds could gust as high as 26 mph.

    Low: 30 °F

    Gradual
    Clearing

  • Thursday

    Thursday: Sunny, with a high near 55. Calm wind becoming southwest 5 to 7 mph in the afternoon.

    High: 55 °F

    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 42. South wind 6 to 13 mph, with gusts as high as 26 mph.

    Low: 42 °F

    Mostly Clear

  • Friday

    Friday: Mostly sunny, with a high near 64. Northwest wind 7 to 9 mph, with gusts as high as 22 mph.

    High: 64 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 34.

    Low: 34 °F

    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 64.

    High: 64 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 50.

    Low: 50 °F

    Mostly Cloudy

  • Sunday

    Sunday: A chance of rain and thunderstorms, then rain likely after 1pm. Mostly cloudy, with a high near 67. Chance of precipitation is 70%.

    High: 67 °F

    Rain Likely

Detailed Forecast

This Afternoon
A 20 percent chance of showers. Cloudy, with a steady temperature around 47. Northwest wind around 15 mph, with gusts as high as 29 mph.
Tonight
Mostly cloudy during the early evening, then gradual clearing, with a low around 30. Northwest wind 8 to 13 mph becoming light after midnight. Winds could gust as high as 26 mph.
Thursday
Sunny, with a high near 55. Calm wind becoming southwest 5 to 7 mph in the afternoon.
Thursday Night
Mostly clear, with a low around 42. South wind 6 to 13 mph, with gusts as high as 26 mph.
Friday
Mostly sunny, with a high near 64. Northwest wind 7 to 9 mph, with gusts as high as 22 mph.
Friday Night
Mostly cloudy, with a low around 34.
Saturday
Partly sunny, with a high near 64.
Saturday Night
Mostly cloudy, with a low around 50.
Sunday
A chance of rain and thunderstorms, then rain likely after 1pm. Mostly cloudy, with a high near 67. Chance of precipitation is 70%.
Sunday Night
A chance of rain and snow before 1am. Mostly cloudy, with a low around 22. Chance of precipitation is 30%.
Monday
Mostly sunny, with a high near 38.
Monday Night
Mostly clear, with a low around 17.
Tuesday
Partly sunny, with a high near 44.
Tuesday Night
A slight chance of rain and snow. Mostly cloudy, with a low around 31. Chance of precipitation is 20%.
Wednesday
Partly sunny, with a high near 58.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Herculaneum MO
 38.27°N 90.39°W (Elev. 456 ft)
Last Update:
3:01 pm CDT Mar 11, 2026
Forecast Valid:
4pm CDT Mar 11, 2026-6pm CDT Mar 18, 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