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

27°F

-3°C

Humidity 72%
Wind Speed N 10 mph
Barometer 30.45 in (1031.6 mb)
Dewpoint 19°F (-7°C)
Visibility 10.00 mi
Wind Chill18°F (-8°C)
Last update 28 Nov 1:53 am CST
Extended Forecast for

Herculaneum MO

  • Overnight

    Overnight: Clear, with a low around 22. Calm wind.

    Low: 22 °F

    Clear

  • Friday

    Friday: Increasing clouds, with a high near 39. Calm wind.

    High: 39 °F

    Increasing
    Clouds

  • Friday Night

    Friday Night: Snow, mainly after midnight. Low around 30. Southeast wind 3 to 7 mph. Chance of precipitation is 90%. New snow accumulation of less than one inch possible.

    Low: 30 °F

    Cloudy then
    Snow

  • Saturday

    Saturday: Snow before 9am, then rain and snow between 9am and 3pm, then rain after 3pm. High near 39. Southeast wind 7 to 10 mph, with gusts as high as 23 mph. Chance of precipitation is 100%. New snow accumulation of 1 to 2 inches possible.

    High: 39 °F

    Rain/Snow

  • Saturday Night

    Saturday Night: Rain likely before midnight. Cloudy, with a low around 24. South wind 7 to 9 mph becoming northwest after midnight. Winds could gust as high as 21 mph. Chance of precipitation is 70%.

    Low: 24 °F

    Rain Likely
    then Cloudy

  • Sunday

    Sunday: Mostly cloudy, with a high near 32.

    High: 32 °F

    Mostly Cloudy

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 16.

    Low: 16 °F

    Mostly Cloudy

  • Monday

    Monday: A 20 percent chance of snow after noon. Mostly cloudy, with a high near 29.

    High: 29 °F

    Mostly Cloudy
    then Slight
    Chance Snow

  • Monday Night

    Monday Night: A 30 percent chance of snow, mainly before midnight. Mostly cloudy, with a low around 18.

    Low: 18 °F

    Chance Snow

Detailed Forecast

Overnight
Clear, with a low around 22. Calm wind.
Friday
Increasing clouds, with a high near 39. Calm wind.
Friday Night
Snow, mainly after midnight. Low around 30. Southeast wind 3 to 7 mph. Chance of precipitation is 90%. New snow accumulation of less than one inch possible.
Saturday
Snow before 9am, then rain and snow between 9am and 3pm, then rain after 3pm. High near 39. Southeast wind 7 to 10 mph, with gusts as high as 23 mph. Chance of precipitation is 100%. New snow accumulation of 1 to 2 inches possible.
Saturday Night
Rain likely before midnight. Cloudy, with a low around 24. South wind 7 to 9 mph becoming northwest after midnight. Winds could gust as high as 21 mph. Chance of precipitation is 70%.
Sunday
Mostly cloudy, with a high near 32.
Sunday Night
Mostly cloudy, with a low around 16.
Monday
A 20 percent chance of snow after noon. Mostly cloudy, with a high near 29.
Monday Night
A 30 percent chance of snow, mainly before midnight. Mostly cloudy, with a low around 18.
Tuesday
Mostly sunny, with a high near 35.
Tuesday Night
Partly cloudy, with a low around 19.
Wednesday
Mostly sunny, with a high near 43.
Wednesday Night
Mostly cloudy, with a low around 25.
Thursday
Mostly cloudy, with a high near 39.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Herculaneum MO
 38.27°N 90.39°W (Elev. 456 ft)
Last Update:
1:26 am CST Nov 28, 2025
Forecast Valid:
2am CST Nov 28, 2025-6pm CST Dec 4, 2025
 
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