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

Hazardous Weather Conditions

Current conditions at

Southern Illinois Airport (KMDH)

Lat: 37.78°NLon: 89.25°WElev: 400ft.

Fair

28°F

-2°C

Humidity 92%
Wind Speed W 5 mph
Barometer 30.21 in (1023.4 mb)
Dewpoint 26°F (-3°C)
Visibility 9.00 mi
Wind Chill22°F (-6°C)
Last update 6 Feb 11:52 pm CST
Extended Forecast for

Saint Johns IL

  • Overnight

    Overnight: Mostly clear, with a low around 22. West northwest wind around 6 mph becoming north northeast.

    Low: 22 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 34. North northeast wind around 6 mph becoming light and variable in the afternoon.

    High: 34 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 24. Southeast wind 3 to 6 mph.

    Low: 24 °F

    Mostly Cloudy

  • Sunday

    Sunday: Mostly sunny, with a high near 48. South wind 5 to 9 mph.

    High: 48 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 30. Light and variable wind.

    Low: 30 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 58. Calm wind becoming south southwest around 5 mph.

    High: 58 °F

    Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 41. South wind 3 to 6 mph.

    Low: 41 °F

    Partly Cloudy

  • Tuesday

    Tuesday: A chance of showers after noon. Mostly cloudy, with a high near 65. South southwest wind 6 to 9 mph.

    High: 65 °F

    Mostly Cloudy
    then Chance
    Showers

  • Tuesday Night

    Tuesday Night: Showers likely. Mostly cloudy, with a low around 43. South southwest wind around 9 mph becoming northwest after midnight.

    Low: 43 °F

    Showers
    Likely

Detailed Forecast

Overnight
Mostly clear, with a low around 22. West northwest wind around 6 mph becoming north northeast.
Saturday
Sunny, with a high near 34. North northeast wind around 6 mph becoming light and variable in the afternoon.
Saturday Night
Mostly cloudy, with a low around 24. Southeast wind 3 to 6 mph.
Sunday
Mostly sunny, with a high near 48. South wind 5 to 9 mph.
Sunday Night
Mostly clear, with a low around 30. Light and variable wind.
Monday
Sunny, with a high near 58. Calm wind becoming south southwest around 5 mph.
Monday Night
Partly cloudy, with a low around 41. South wind 3 to 6 mph.
Tuesday
A chance of showers after noon. Mostly cloudy, with a high near 65. South southwest wind 6 to 9 mph.
Tuesday Night
Showers likely. Mostly cloudy, with a low around 43. South southwest wind around 9 mph becoming northwest after midnight.
Wednesday
A chance of showers. Mostly cloudy, with a high near 53. North northwest wind 7 to 10 mph.
Wednesday Night
A slight chance of showers. Mostly cloudy, with a low around 33. North wind around 6 mph.
Thursday
A slight chance of showers. Mostly cloudy, with a high near 47. North wind around 7 mph.
Thursday Night
A chance of showers. Mostly cloudy, with a low around 31. North northeast wind around 6 mph.
Friday
A slight chance of showers. Partly sunny, with a high near 46. North northeast wind 6 to 8 mph.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Saint Johns IL
 38.03°N 89.24°W
Last Update:
12:22 am CST Feb 7, 2026
Forecast Valid:
12am CST Feb 7, 2026-6pm CST Feb 13, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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