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.

Fog/Mist

67°F

19°C

Humidity 97%
Wind Speed S 3 mph
Barometer 30.05 in (1017.4 mb)
Dewpoint 66°F (19°C)
Visibility 6.00 mi
Last update 15 Oct 1:53 am CDT
Extended Forecast for

Herculaneum MO

  • Overnight

    Overnight: A 30 percent chance of showers and thunderstorms, mainly after 4am. Mostly cloudy, with a low around 67. Calm wind.

    Low: 67 °F

    Chance
    T-storms

  • Thursday

    Thursday: Showers likely and possibly a thunderstorm before noon, then a chance of showers and thunderstorms after noon. 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 isolated 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 37. North wind 7 to 14 mph, with gusts as high as 25 mph.

    Low: 37 °F

    Mostly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 61.

    High: 61 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 34.

    Low: 34 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 67.

    High: 67 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 37.

    Low: 37 °F

    Mostly Clear

Detailed Forecast

Overnight
A 30 percent chance of showers and thunderstorms, mainly after 4am. Mostly cloudy, with a low around 67. Calm wind.
Thursday
Showers likely and possibly a thunderstorm before noon, then a chance of showers and thunderstorms after noon. 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 isolated 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 37. North wind 7 to 14 mph, with gusts as high as 25 mph.
Saturday
Sunny, with a high near 61.
Saturday Night
Clear, with a low around 34.
Sunday
Sunny, with a high near 67.
Sunday Night
Mostly clear, with a low around 37.
Monday
Mostly sunny, with a high near 73.
Monday Night
Partly cloudy, with a low around 39.
Tuesday
Sunny, with a high near 75.
Tuesday Night
Mostly clear, with a low around 42.
Wednesday
Sunny, with a high near 78.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Herculaneum MO
 38.27°N 90.39°W (Elev. 456 ft)
Last Update:
1:26 am CDT Oct 15, 2026
Forecast Valid:
2am CDT Oct 15, 2026-6pm CDT Oct 21, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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