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.

N/A

Humidity NA
Wind Speed NA
Barometer NA
Dewpoint N/A
Visibility NA
Last update *** Not a current observation ***
Extended Forecast for

Saint Johns IL

  • Today

    Today: A 20 percent chance of snow after 5pm. Increasing clouds, with a high near 29. Wind chill values as low as -3. Calm wind becoming south 5 to 9 mph in the morning.

    High: 29 °F

    Mostly Sunny
    then Slight
    Chance Snow

  • Tonight

    Tonight: A 50 percent chance of snow before 11pm. Mostly cloudy, with a low around 19. South southwest wind 5 to 8 mph.

    Low: 19 °F

    Chance Snow
    then Mostly
    Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 38. Southwest wind 3 to 6 mph.

    High: 38 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 25. Calm wind.

    Low: 25 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: A 20 percent chance of snow showers. Mostly cloudy, with a high near 35. Calm wind becoming north 5 to 7 mph in the morning.

    High: 35 °F

    Slight Chance
    Snow Showers

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 18. North wind around 6 mph.

    Low: 18 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 30. North wind 5 to 7 mph.

    High: 30 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 11. Light and variable wind.

    Low: 11 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 35. Calm wind becoming south 5 to 8 mph in the morning.

    High: 35 °F

    Mostly Sunny

Detailed Forecast

Today
A 20 percent chance of snow after 5pm. Increasing clouds, with a high near 29. Wind chill values as low as -3. Calm wind becoming south 5 to 9 mph in the morning.
Tonight
A 50 percent chance of snow before 11pm. Mostly cloudy, with a low around 19. South southwest wind 5 to 8 mph.
Monday
Mostly sunny, with a high near 38. Southwest wind 3 to 6 mph.
Monday Night
Mostly cloudy, with a low around 25. Calm wind.
Tuesday
A 20 percent chance of snow showers. Mostly cloudy, with a high near 35. Calm wind becoming north 5 to 7 mph in the morning.
Tuesday Night
Mostly cloudy, with a low around 18. North wind around 6 mph.
Wednesday
Mostly sunny, with a high near 30. North wind 5 to 7 mph.
Wednesday Night
Partly cloudy, with a low around 11. Light and variable wind.
Thursday
Mostly sunny, with a high near 35. Calm wind becoming south 5 to 8 mph in the morning.
Thursday Night
Partly cloudy, with a low around 27. South wind 8 to 10 mph becoming west southwest after midnight. Winds could gust as high as 18 mph.
Friday
Mostly sunny, with a high near 45. West southwest wind 8 to 10 mph becoming northwest in the afternoon. Winds could gust as high as 18 mph.
Friday Night
Partly cloudy, with a low around 21. North northwest wind around 7 mph.
Saturday
Mostly sunny, with a high near 32. North wind around 6 mph becoming east in the afternoon.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Saint Johns IL
 38.03°N 89.24°W
Last Update:
4:46 am CST Feb 1, 2026
Forecast Valid:
5am CST Feb 1, 2026-6pm CST Feb 7, 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