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Hazardous Weather Conditions

Current conditions at

Southern Illinois Airport (KMDH)

Lat: 37.78°NLon: 89.25°WElev: 400ft.

Fair

55°F

13°C

Humidity 64%
Wind Speed SE 5 mph
Barometer 29.81 in (1009.6 mb)
Dewpoint 43°F (6°C)
Visibility 10.00 mi
Wind Chill54°F (12°C)
Last update 14 Mar 10:52 pm CDT
Extended Forecast for

Saint Johns IL

Wind Advisory March 15, 10:00am until March 16, 07:00am
Click here for hazard details and duration
Wind Advisory

  • Tonight

    Tonight: Partly cloudy, with a low around 55. South wind 6 to 13 mph, with gusts as high as 21 mph.

    Low: 55 °F

    Partly Cloudy

  • Sunday

    Sunday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 4pm. Mostly cloudy, with a high near 68. Breezy, with a south wind 17 to 22 mph increasing to 23 to 28 mph in the afternoon. Winds could gust as high as 40 mph. Chance of precipitation is 60%.

    High: 68 °F

    Breezy.
    Slight Chance
    Showers then
    Showers
    Likely

  • Sunday Night

    Sunday Night: Rain showers before 10pm, then rain and snow showers between 10pm and 1am, then a slight chance of snow showers after 1am. Some thunder is also possible. Low around 23. Breezy, with a west northwest wind 22 to 25 mph, with gusts as high as 41 mph. Chance of precipitation is 80%. New snow accumulation of less than a half inch possible.

    Low: 23 °F

    Rain/Snow and
    Breezy

  • Monday

    Monday: Mostly cloudy, with a high near 32. Breezy, with a west northwest wind 20 to 22 mph, with gusts as high as 37 mph.

    High: 32 °F

    Mostly Cloudy
    and Breezy

  • Monday Night

    Monday Night: Mostly clear, with a low around 15. West northwest wind 9 to 18 mph, with gusts as high as 26 mph.

    Low: 15 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 38. Northwest wind around 7 mph becoming southwest in the afternoon.

    High: 38 °F

    Sunny

  • Tuesday Night

    Tuesday Night: A 20 percent chance of snow showers after 1am. Mostly cloudy, with a low around 30. South southeast wind 5 to 14 mph, with gusts as high as 23 mph.

    Low: 30 °F

    Mostly Cloudy
    then Slight
    Chance Snow
    Showers

  • Wednesday

    Wednesday: Mostly sunny, with a high near 62. South wind 11 to 15 mph, with gusts as high as 24 mph.

    High: 62 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 40. South southwest wind 5 to 7 mph.

    Low: 40 °F

    Partly Cloudy

Detailed Forecast

Tonight
Partly cloudy, with a low around 55. South wind 6 to 13 mph, with gusts as high as 21 mph.
Sunday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 4pm. Mostly cloudy, with a high near 68. Breezy, with a south wind 17 to 22 mph increasing to 23 to 28 mph in the afternoon. Winds could gust as high as 40 mph. Chance of precipitation is 60%.
Sunday Night
Rain showers before 10pm, then rain and snow showers between 10pm and 1am, then a slight chance of snow showers after 1am. Some thunder is also possible. Low around 23. Breezy, with a west northwest wind 22 to 25 mph, with gusts as high as 41 mph. Chance of precipitation is 80%. New snow accumulation of less than a half inch possible.
Monday
Mostly cloudy, with a high near 32. Breezy, with a west northwest wind 20 to 22 mph, with gusts as high as 37 mph.
Monday Night
Mostly clear, with a low around 15. West northwest wind 9 to 18 mph, with gusts as high as 26 mph.
Tuesday
Sunny, with a high near 38. Northwest wind around 7 mph becoming southwest in the afternoon.
Tuesday Night
A 20 percent chance of snow showers after 1am. Mostly cloudy, with a low around 30. South southeast wind 5 to 14 mph, with gusts as high as 23 mph.
Wednesday
Mostly sunny, with a high near 62. South wind 11 to 15 mph, with gusts as high as 24 mph.
Wednesday Night
Partly cloudy, with a low around 40. South southwest wind 5 to 7 mph.
Thursday
Sunny, with a high near 71. South southwest wind around 6 mph.
Thursday Night
Partly cloudy, with a low around 47. South wind around 6 mph.
Friday
Sunny, with a high near 72. South wind 6 to 8 mph becoming west in the afternoon.
Friday Night
Partly cloudy, with a low around 48. West wind around 7 mph.
Saturday
Mostly sunny, with a high near 76. West northwest wind 7 to 10 mph.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Saint Johns IL
 38.03°N 89.24°W
Last Update:
9:06 pm CDT Mar 14, 2026
Forecast Valid:
11pm CDT Mar 14, 2026-6pm CDT Mar 21, 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