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

  • Overnight

    Overnight: A 40 percent chance of showers, mainly between 1am and 5am.  Mostly cloudy, with a low around 37. Northeast wind 3 to 6 mph.

    Low: 37 °F

    Chance
    Showers

  • Thursday

    Thursday: Mostly sunny, with a high near 57. East northeast wind around 6 mph becoming calm  in the afternoon.

    High: 57 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 36. Light and variable wind.

    Low: 36 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 66. Light south southwest wind becoming southwest 5 to 10 mph in the morning.

    High: 66 °F

    Sunny

  • Friday Night

    Friday Night: Clear, with a low around 42. South wind 5 to 8 mph becoming northwest after midnight.

    Low: 42 °F

    Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 65. North northwest wind 5 to 9 mph becoming south southeast in the afternoon.

    High: 65 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: A 20 percent chance of showers before midnight.  Partly cloudy, with a low around 34. North northeast wind 9 to 11 mph, with gusts as high as 20 mph.

    Low: 34 °F

    Slight Chance
    Showers then
    Mostly Cloudy

  • Sunday

    Sunday: A chance of showers after noon.  Cloudy, with a high near 48. East northeast wind around 11 mph, with gusts as high as 18 mph.

    High: 48 °F

    Mostly Cloudy
    then Chance
    Showers

  • Sunday Night

    Sunday Night: Rain likely, possibly mixed with snow showers.  Cloudy, with a low around 32. Northeast wind around 10 mph, with gusts as high as 18 mph.

    Low: 32 °F

    Rain/Snow
    Likely

Detailed Forecast

Overnight
A 40 percent chance of showers, mainly between 1am and 5am. Mostly cloudy, with a low around 37. Northeast wind 3 to 6 mph.
Thursday
Mostly sunny, with a high near 57. East northeast wind around 6 mph becoming calm in the afternoon.
Thursday Night
Mostly clear, with a low around 36. Light and variable wind.
Friday
Sunny, with a high near 66. Light south southwest wind becoming southwest 5 to 10 mph in the morning.
Friday Night
Clear, with a low around 42. South wind 5 to 8 mph becoming northwest after midnight.
Saturday
Mostly sunny, with a high near 65. North northwest wind 5 to 9 mph becoming south southeast in the afternoon.
Saturday Night
A 20 percent chance of showers before midnight. Partly cloudy, with a low around 34. North northeast wind 9 to 11 mph, with gusts as high as 20 mph.
Sunday
A chance of showers after noon. Cloudy, with a high near 48. East northeast wind around 11 mph, with gusts as high as 18 mph.
Sunday Night
Rain likely, possibly mixed with snow showers. Cloudy, with a low around 32. Northeast wind around 10 mph, with gusts as high as 18 mph.
Monday
A chance of rain and snow showers before noon, then a slight chance of rain showers. Cloudy, with a high near 43. Northeast wind 9 to 11 mph, with gusts as high as 18 mph.
Monday Night
A chance of showers. Cloudy, with a low around 32. East northeast wind 6 to 8 mph.
Tuesday
A chance of showers. Cloudy, with a high near 48. East wind 6 to 8 mph becoming west in the afternoon.
Tuesday Night
A chance of showers. Cloudy, with a low around 35. North northeast wind around 6 mph.
Wednesday
A chance of showers. Mostly cloudy, with a high near 55. East wind 6 to 8 mph.
Basemap Options
Click map to change the forecast location
Loading map...

ABOUT THIS FORECAST

 
Point Forecast:
Saint Johns IL
 38.03°N 89.24°W
12:01 am CST Feb 26, 2026
12am CST Feb 26, 2026-6pm CST Mar 4, 2026
 
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