Current conditions at

Southern Illinois Airport (KMDH)

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

Fair

84°F

29°C

Humidity 74%
Wind Speed S 5 mph
Barometer 30.04 in
Dewpoint 75°F (24°C)
Visibility 10.00 mi
Heat Index92°F (33°C)
Last update 15 Aug 7:52 pm CDT
Detailed forecast for

Union County

Tonight
Mostly clear. Lows in the mid 70s. South winds around 5 mph.
Sunday
Sunny, hot with highs in the upper 90s. Southwest winds around 5 mph. Highest heat index readings heat index readings up to 107 in the afternoon.
Sunday Night
A chance of showers in the evening. Partly cloudy. Lows in the lower 70s. Northwest winds around 5 mph. Chance of rain 30 percent.
Monday
A chance of showers in the morning. Mostly sunny. Highs in the upper 80s. North winds around 5 mph. Chance of rain 40 percent.
Monday Night
Partly cloudy in the evening, then becoming mostly clear. Lows in the upper 60s. North winds around 5 mph in the evening, becoming light and variable.
Tuesday And Tuesday Night
Mostly clear. Highs around 90. Lows around 70.
Wednesday
Mostly sunny. Highs in the mid 90s.
Wednesday Night
Partly cloudy in the evening, then becoming mostly cloudy. A chance of showers and thunderstorms. Lows in the upper 60s. Chance of rain 50 percent.
Thursday
Partly sunny. Highs in the mid 80s.
Thursday Night Through Saturday
Partly cloudy. Lows in the mid 60s. Highs in the mid 80s.



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817 PM CDT Sat Aug 15 2026
 
 

Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database