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

Hazardous Weather Conditions

Current conditions at

Marion - Williamson County Regional Airport (KMWA)

Lat: 37.77°NLon: 89.01°WElev: 486ft.

Partly Cloudy

82°F

28°C

Humidity 74%
Wind Speed S 14 mph
Barometer 29.76 in
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Heat Index87°F (31°C)
Last update 21 Jun 4:45 pm CDT
Extended Forecast for

4 Miles SW Simpson IL

  • This Afternoon

    This Afternoon: A 30 percent chance of showers and thunderstorms, mainly after 5pm. Mostly cloudy, with a steady temperature around 82. South wind around 9 mph, with gusts as high as 23 mph.

    High: 82 °F

    Chance
    T-storms

  • Tonight

    Tonight: Showers and thunderstorms before 3am, then showers likely and possibly a thunderstorm between 3am and 4am, then a chance of showers and thunderstorms after 4am. Low around 70. South southwest wind 6 to 10 mph, with gusts as high as 21 mph. Chance of precipitation is 90%.

    Low: 70 °F

    T-storms

  • Monday

    Monday: A 50 percent chance of showers and thunderstorms before 1pm. Mostly cloudy, with a high near 80. North northwest wind 6 to 8 mph.

    High: 80 °F

    Chance
    T-storms then
    Chance
    Showers

  • Monday Night

    Monday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 62. North wind around 6 mph becoming calm in the evening.

    Low: 62 °F

    Decreasing
    Clouds

  • Tuesday

    Tuesday: Sunny, with a high near 82. Light northeast wind.

    High: 82 °F

    Sunny

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers after 1am. Mostly clear, with a low around 62. Calm wind.

    Low: 62 °F

    Mostly Clear
    then Slight
    Chance
    Showers

  • Wednesday

    Wednesday: A 30 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 85. Light and variable wind.

    High: 85 °F

    Mostly Sunny
    then Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 68. Calm wind.

    Low: 68 °F

    Slight Chance
    T-storms

  • Thursday

    Thursday: A chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 86. Calm wind becoming southwest around 5 mph.

    High: 86 °F

    Chance
    T-storms

Detailed Forecast

This Afternoon
A 30 percent chance of showers and thunderstorms, mainly after 5pm. Mostly cloudy, with a steady temperature around 82. South wind around 9 mph, with gusts as high as 23 mph.
Tonight
Showers and thunderstorms before 3am, then showers likely and possibly a thunderstorm between 3am and 4am, then a chance of showers and thunderstorms after 4am. Low around 70. South southwest wind 6 to 10 mph, with gusts as high as 21 mph. Chance of precipitation is 90%.
Monday
A 50 percent chance of showers and thunderstorms before 1pm. Mostly cloudy, with a high near 80. North northwest wind 6 to 8 mph.
Monday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 62. North wind around 6 mph becoming calm in the evening.
Tuesday
Sunny, with a high near 82. Light northeast wind.
Tuesday Night
A 20 percent chance of showers after 1am. Mostly clear, with a low around 62. Calm wind.
Wednesday
A 30 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 85. Light and variable wind.
Wednesday Night
A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 68. Calm wind.
Thursday
A chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 86. Calm wind becoming southwest around 5 mph.
Thursday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 66. Calm wind.
Friday
A chance of showers and thunderstorms. Mostly sunny, with a high near 87. Calm wind becoming south around 5 mph in the afternoon.
Friday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 70. Calm wind.
Saturday
A chance of showers and thunderstorms. Partly sunny, with a high near 88. Southwest wind 3 to 8 mph.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
4 Miles SW Simpson IL
 37.44°N 88.82°W
Last Update:
4:06 pm CDT Jun 21, 2026
Forecast Valid:
4pm CDT Jun 21, 2026-6pm CDT Jun 27, 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