Extreme Heat in the Southwest; Severe Weather in the Northern Plains; Heavy Rain in the East

Extreme heat continues across the Southwest as temperatures may top 120 degrees. The heat may expand across the West and south-central U.S. into the middle of the month. Severe thunderstorms capable of severe wind gusts and large hail will be the primary hazards today across the northern Plains into the upper Midwest. Rainfall could be locally heavy across the Eastern U.S. today. Read More >

Current conditions at

St. Charles, St. Charles County Smartt Airport (KSET)

Lat: 38.93°NLon: 90.43°WElev: 436ft.

Fair

78°F

26°C

Humidity 62%
Wind Speed Calm
Barometer 29.99 in (1015.1 mb)
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 3 Aug 10:54 am CDT
Extended Forecast for

4 Miles E Portage Des Sioux MO

  • Today

    Today: Mostly sunny, with a high near 86. Light northeast wind.

    High: 86 °F

    Mostly Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 65. East wind around 5 mph becoming calm  in the evening.

    Low: 65 °F

    Mostly Clear

  • Tuesday

    Tuesday: Patchy fog before 7am.  Otherwise, sunny, with a high near 88. Calm wind becoming south around 5 mph in the morning.

    High: 88 °F

    Patchy Fog
    then Sunny

  • Tuesday Night

    Tuesday Night: 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 90. Calm wind becoming south around 6 mph in the morning.

    High: 90 °F

    Sunny

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am.  Mostly cloudy, with a low around 70. Chance of precipitation is 70%.

    Low: 70 °F

    Chance
    T-storms then
    Showers
    Likely

  • Thursday

    Thursday: Showers likely and possibly a thunderstorm before 1pm.  Mostly cloudy, with a high near 85. Chance of precipitation is 70%.

    High: 85 °F

    Showers
    Likely

  • Thursday Night

    Thursday Night: A 50 percent chance of showers and thunderstorms.  Mostly cloudy, with a low around 69.

    Low: 69 °F

    Chance
    T-storms

  • Friday

    Friday: A 20 percent chance of showers and thunderstorms.  Partly sunny, with a high near 86.

    High: 86 °F

    Slight Chance
    T-storms

Detailed Forecast

Today
Mostly sunny, with a high near 86. Light northeast wind.
Tonight
Mostly clear, with a low around 65. East wind around 5 mph becoming calm in the evening.
Tuesday
Patchy fog before 7am. Otherwise, sunny, with a high near 88. Calm wind becoming south around 5 mph in the morning.
Tuesday Night
Mostly clear, with a low around 68. Southeast wind 3 to 5 mph.
Wednesday
Sunny, with a high near 90. Calm wind becoming south around 6 mph in the morning.
Wednesday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 70. Chance of precipitation is 70%.
Thursday
Showers likely and possibly a thunderstorm before 1pm. Mostly cloudy, with a high near 85. Chance of precipitation is 70%.
Thursday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 69.
Friday
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 86.
Friday Night
A 30 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 69.
Saturday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 88.
Saturday Night
Partly cloudy, with a low around 71.
Sunday
Mostly sunny, with a high near 92.
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ABOUT THIS FORECAST

 
Point Forecast:
4 Miles E Portage Des Sioux MO
 38.93°N 90.27°W (Elev. 407 ft)
10:51 am CDT Aug 3, 2026
11am CDT Aug 3, 2026-6pm CDT Aug 9, 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