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

Dangerous Heat over the South-Central and Southwest U.S. Through Next Week

Dangerous heat persists across the Desert Southwest through this weekend and across the Southern Plains and Lower Mississippi Valley through at least the middle of next week. Numerous daily record high temperatures are expected through at least Tuesday for much of Texas and Oklahoma as well as portions of Louisiana, New Mexico, and Arizona. Read More >

Current conditions at

St. Louis Lambert International Airport (KSTL)

Lat: 38.75°NLon: 90.37°WElev: 604ft.

Partly Cloudy

74°F

23°C

Humidity 71%
Wind Speed NW 7 mph
Barometer 30.06 in (1016.6 mb)
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Last update 22 Aug 11:51 pm CDT
Extended Forecast for

Saint Charles MO

  • Overnight

    Overnight: Mostly clear, with a low around 64. Light northwest wind.

    Low: 64 °F

    Mostly Clear

  • Sunday

    Sunday: Increasing clouds, with a high near 81. Northwest wind 3 to 8 mph.

    High: 81 °F

    Increasing
    Clouds

  • Sunday Night

    Sunday Night: Cloudy, then gradual clearing toward daybreak, with a low around 63. North wind around 5 mph becoming calm in the evening.

    Low: 63 °F

    Clearing Late

  • Monday

    Monday: Increasing clouds, with a high near 82. Calm wind becoming southeast around 5 mph in the afternoon.

    High: 82 °F

    Increasing
    Clouds

  • Monday Night

    Monday Night: A slight chance of showers and thunderstorms. Partly cloudy, with a low around 66. Southeast wind 3 to 5 mph. Chance of precipitation is 20%.

    Low: 66 °F

    Slight Chance
    T-storms

  • Tuesday

    Tuesday: Mostly sunny, with a high near 85.

    High: 85 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 69.

    Low: 69 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Partly sunny, with a high near 87.

    High: 87 °F

    Partly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 69.

    Low: 69 °F

    Partly Cloudy

Detailed Forecast

Overnight
Mostly clear, with a low around 64. Light northwest wind.
Sunday
Increasing clouds, with a high near 81. Northwest wind 3 to 8 mph.
Sunday Night
Cloudy, then gradual clearing toward daybreak, with a low around 63. North wind around 5 mph becoming calm in the evening.
Monday
Increasing clouds, with a high near 82. Calm wind becoming southeast around 5 mph in the afternoon.
Monday Night
A slight chance of showers and thunderstorms. Partly cloudy, with a low around 66. Southeast wind 3 to 5 mph. Chance of precipitation is 20%.
Tuesday
Mostly sunny, with a high near 85.
Tuesday Night
Partly cloudy, with a low around 69.
Wednesday
Partly sunny, with a high near 87.
Wednesday Night
Partly cloudy, with a low around 69.
Thursday
Sunny, with a high near 86.
Thursday Night
Mostly clear, with a low around 67.
Friday
Sunny, with a high near 85.
Friday Night
Partly cloudy, with a low around 69.
Saturday
A 20 percent chance of showers. Mostly sunny, with a high near 87.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Saint Charles MO
 38.78°N 90.51°W (Elev. 597 ft)
Last Update:
11:16 pm CDT Aug 22, 2026
Forecast Valid:
12am CDT Aug 23, 2026-6pm CDT Aug 29, 2026
 
Forecast Discussion
 
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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