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.

Mostly Cloudy and Breezy

36°F

2°C

Humidity 46%
Wind Speed NW 23 G 37 mph
Barometer 30.02 in (1016.9 mb)
Dewpoint 17°F (-8°C)
Visibility 10.00 mi
Wind Chill24°F (-4°C)
Last update 14 Jan 3:53 pm CST
Extended Forecast for

Herculaneum MO

  • Tonight

    Tonight: Clear, with a low around 16. Northwest wind 5 to 10 mph, with gusts as high as 28 mph.

    Low: 16 °F

    Clear

  • Thursday

    Thursday: Sunny, with a high near 36. Northwest wind around 5 mph becoming light and variable in the afternoon.

    High: 36 °F

    Sunny

  • Thursday Night

    Thursday Night: A chance of snow before 11pm, then a chance of rain between 11pm and 3am, then a slight chance of snow after 3am. Mostly cloudy, with a low around 28. Light and variable wind becoming south around 6 mph in the evening. Chance of precipitation is 30%.

    Low: 28 °F

    Chance
    Rain/Snow

  • Friday

    Friday: Partly sunny, with a high near 46. West wind 6 to 11 mph, with gusts as high as 25 mph.

    High: 46 °F

    Partly Sunny

  • Friday Night

    Friday Night: A chance of sprinkles before 8pm, then a chance of flurries between 8pm and midnight, then a slight chance of snow showers after midnight. Mostly cloudy, with a low around 19. West wind around 8 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.

    Low: 19 °F

    Chance
    Sprinkles/Flurries
    then Slight
    Chance Snow
    Showers

  • Saturday

    Saturday: Partly sunny, with a high near 28.

    High: 28 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 7.

    Low: 7 °F

    Partly Cloudy

  • Sunday

    Sunday: Mostly sunny, with a high near 27.

    High: 27 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 14.

    Low: 14 °F

    Partly Cloudy

Detailed Forecast

Tonight
Clear, with a low around 16. Northwest wind 5 to 10 mph, with gusts as high as 28 mph.
Thursday
Sunny, with a high near 36. Northwest wind around 5 mph becoming light and variable in the afternoon.
Thursday Night
A chance of snow before 11pm, then a chance of rain between 11pm and 3am, then a slight chance of snow after 3am. Mostly cloudy, with a low around 28. Light and variable wind becoming south around 6 mph in the evening. Chance of precipitation is 30%.
Friday
Partly sunny, with a high near 46. West wind 6 to 11 mph, with gusts as high as 25 mph.
Friday Night
A chance of sprinkles before 8pm, then a chance of flurries between 8pm and midnight, then a slight chance of snow showers after midnight. Mostly cloudy, with a low around 19. West wind around 8 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.
Saturday
Partly sunny, with a high near 28.
Saturday Night
Partly cloudy, with a low around 7.
Sunday
Mostly sunny, with a high near 27.
Sunday Night
Partly cloudy, with a low around 14.
M.L.King Day
Mostly sunny, with a high near 29.
Monday Night
Mostly clear, with a low around 10.
Tuesday
Sunny, with a high near 35.
Tuesday Night
Mostly clear, with a low around 20.
Wednesday
Sunny, with a high near 45.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Herculaneum MO
 38.25°N 90.39°W (Elev. 499 ft)
Last Update:
4:51 pm CST Jan 14, 2026
Forecast Valid:
4pm CST Jan 14, 2026-6pm CST Jan 21, 2026
 
Forecast Discussion
 
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Additional Resources

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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