National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

St. Louis Downtown Airport (KCPS)

Lat: 38.56°NLon: 90.15°WElev: 410ft.

A Few Clouds

82°F

28°C

Humidity 55%
Wind Speed SW 7 G 16 mph
Barometer 30.07 in (1017.8 mb)
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 24 Jun 12:53 pm CDT
Extended Forecast for

Herculaneum MO

Flood Watch June 25, 01:00pm until June 26, 07:00am
Click here for hazard details and duration
Flood Watch

  • This Afternoon

    This Afternoon: A 30 percent chance of showers and thunderstorms, mainly after 5pm. Partly sunny, with a high near 83. Southwest wind 3 to 5 mph.

    High: 83 °F

    Chance
    T-storms

  • Tonight

    Tonight: A 30 percent chance of showers and thunderstorms, mainly after 4am. Partly cloudy, with a low around 66. Calm wind.

    Low: 66 °F

    Chance
    T-storms

  • Thursday

    Thursday: A 40 percent chance of showers and thunderstorms, mainly after noon. Partly sunny, with a high near 85. Calm wind.

    High: 85 °F

    Chance
    T-storms

  • Thursday Night

    Thursday Night: Showers and thunderstorms likely, then showers and possibly a thunderstorm after 1am. Low around 68. Calm wind. Chance of precipitation is 90%.

    Low: 68 °F

    T-storms
    Likely then
    T-storms

  • Friday

    Friday: Showers and possibly a thunderstorm before 1pm, then showers and thunderstorms likely after 1pm. High near 84. Calm wind becoming southwest around 6 mph in the afternoon. Chance of precipitation is 80%.

    High: 84 °F

    T-storms

  • Friday Night

    Friday Night: Showers and thunderstorms likely. Mostly cloudy, with a low around 68. Chance of precipitation is 70%.

    Low: 68 °F

    T-storms
    Likely

  • Saturday

    Saturday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 88. Chance of precipitation is 60%.

    High: 88 °F

    Chance
    T-storms then
    Showers
    Likely

  • Saturday Night

    Saturday Night: A 30 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 71.

    Low: 71 °F

    Chance
    T-storms

  • Sunday

    Sunday: Mostly sunny, with a high near 94.

    High: 94 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
A 30 percent chance of showers and thunderstorms, mainly after 5pm. Partly sunny, with a high near 83. Southwest wind 3 to 5 mph.
Tonight
A 30 percent chance of showers and thunderstorms, mainly after 4am. Partly cloudy, with a low around 66. Calm wind.
Thursday
A 40 percent chance of showers and thunderstorms, mainly after noon. Partly sunny, with a high near 85. Calm wind.
Thursday Night
Showers and thunderstorms likely, then showers and possibly a thunderstorm after 1am. Low around 68. Calm wind. Chance of precipitation is 90%.
Friday
Showers and possibly a thunderstorm before 1pm, then showers and thunderstorms likely after 1pm. High near 84. Calm wind becoming southwest around 6 mph in the afternoon. Chance of precipitation is 80%.
Friday Night
Showers and thunderstorms likely. Mostly cloudy, with a low around 68. Chance of precipitation is 70%.
Saturday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 88. Chance of precipitation is 60%.
Saturday Night
A 30 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 71.
Sunday
Mostly sunny, with a high near 94.
Sunday Night
Mostly clear, with a low around 75.
Monday
Sunny, with a high near 96.
Monday Night
Clear, with a low around 76.
Tuesday
Sunny, with a high near 96.
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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:
12:46 pm CDT Jun 24, 2026
Forecast Valid:
1pm CDT Jun 24, 2026-6pm CDT Jun 30, 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