Heat Persists in the Southwest; Elevated to Critical Fire Weather in the Great Basin; Poor Air Quality in the West

Dangerous heat will persist across the Southwest U.S. through this week, easing by next week. The heat will focus further east in the Great Plains and Mississippi Valley beginning next week. Elevated to locally critical fire weather conditions will persist for the Great Basin today. Poor air quality lingers for the Northwest, Great Basin, Central Rockies into the Plains. Read More >

Current conditions at

St. Louis Downtown Airport (KCPS)

Lat: 38.56°NLon: 90.15°WElev: 410ft.

Fair

86°F

30°C

Humidity 53%
Wind Speed SE 3 mph
Barometer 30.02 in (1016.2 mb)
Dewpoint 67°F (19°C)
Visibility 10.00 mi
Heat Index89°F (32°C)
Last update 4 Aug 12:53 pm CDT
Extended Forecast for

2 Miles WSW O'Fallon IL

  • This Afternoon

    This Afternoon: Sunny, with a high near 87. Southeast wind 3 to 5 mph.

    High: 87 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 68. Southeast wind 3 to 5 mph.

    Low: 68 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 91. South wind 3 to 8 mph.

    High: 91 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Showers and thunderstorms likely, mainly after 5am.  Cloudy, then gradually becoming partly cloudy, with a low around 72. South wind 3 to 7 mph.  Chance of precipitation is 60%.

    Low: 72 °F

    T-storms
    Likely

  • Thursday

    Thursday: Showers and thunderstorms, mainly before 1pm.  High near 85. North wind around 6 mph becoming south in the morning.  Chance of precipitation is 80%.

    High: 85 °F

    T-storms

  • Thursday Night

    Thursday Night: A 40 percent chance of showers and thunderstorms.  Mostly cloudy, with a low around 71.

    Low: 71 °F

    Chance
    T-storms

  • Friday

    Friday: A 30 percent chance of showers and thunderstorms.  Mostly cloudy, with a high near 86.

    High: 86 °F

    Chance
    Showers then
    Chance
    T-storms

  • Friday Night

    Friday Night: A 40 percent chance of showers and thunderstorms.  Partly cloudy, with a low around 70.

    Low: 70 °F

    Chance
    T-storms

  • Saturday

    Saturday: Mostly sunny, with a high near 89.

    High: 89 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
Sunny, with a high near 87. Southeast wind 3 to 5 mph.
Tonight
Mostly clear, with a low around 68. Southeast wind 3 to 5 mph.
Wednesday
Sunny, with a high near 91. South wind 3 to 8 mph.
Wednesday Night
Showers and thunderstorms likely, mainly after 5am. Cloudy, then gradually becoming partly cloudy, with a low around 72. South wind 3 to 7 mph. Chance of precipitation is 60%.
Thursday
Showers and thunderstorms, mainly before 1pm. High near 85. North wind around 6 mph becoming south in the morning. Chance of precipitation is 80%.
Thursday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 71.
Friday
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 86.
Friday Night
A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 70.
Saturday
Mostly sunny, with a high near 89.
Saturday Night
Mostly clear, with a low around 72.
Sunday
Mostly sunny, with a high near 91.
Sunday Night
Mostly clear, with a low around 75.
Monday
Sunny, with a high near 95.
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ABOUT THIS FORECAST

 
Point Forecast:
2 Miles WSW O'Fallon IL
 38.59°N 89.95°W (Elev. 545 ft)
1:26 pm CDT Aug 4, 2026
1pm CDT Aug 4, 2026-6pm CDT Aug 10, 2026
 
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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