Current conditions at

Southern Illinois Airport (KMDH)

Lat: 37.78° N Lon: 89.25° W Elev: 400 ft.

Clear

70°F

21°C

Humidity 83%
Wind Speed S 3 mph
Barometer 29.91 in
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Last update 20 Sep 5:47 am CDT
Detailed forecast for

Union County

Today
Mostly sunny. Hot with highs in the upper 90s. West winds around 5 mph.
Tonight
Partly cloudy in the evening, then mostly cloudy with a slight chance of showers and thunderstorms after midnight. Lows around 70. North winds around 5 mph. Chance of rain 20 percent.
Monday
Mostly sunny. A chance of showers and thunderstorms in the afternoon. Highs in the upper 80s. North winds around 5 mph. Chance of rain 30 percent.
Monday Night
Partly cloudy. A chance of showers after midnight. Lows in the mid 60s. North winds 5 to 10 mph. Chance of rain 30 percent.
Tuesday
Mostly sunny. Highs in the upper 70s. North winds 5 to 10 mph.
Tuesday Night And Wednesday
Partly cloudy. Lows in the upper 50s. Highs in the mid 70s.
Wednesday Night
Mostly clear. Lows in the mid 50s.
Thursday Through Saturday
Partly cloudy. Highs in the upper 70s. Lows in the mid 50s.



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427 AM CDT Sun Sep 20 2026
 
 

Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database