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

84°F

29°C

Humidity 44%
Wind Speed S 14 G 22 mph
Barometer 29.69 in (1005.0 mb)
Dewpoint 60°F (16°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 22 Mar 12:52 pm CDT
Extended Forecast for

Saint Johns IL

  • This Afternoon

    This Afternoon: A 10 percent chance of showers and thunderstorms after 5pm. Sunny, with a high near 86. South southwest wind 10 to 14 mph, with gusts as high as 21 mph.

    High: 86 °F

    Slight Chance
    T-storms

  • Tonight

    Tonight: A chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 11pm. Mostly cloudy, then gradually becoming clear, with a low around 35. North wind 14 to 18 mph, with gusts as high as 29 mph. Chance of precipitation is 30%.

    Low: 35 °F

    Chance
    T-storms then
    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 55. North northeast wind around 11 mph, with gusts as high as 20 mph.

    High: 55 °F

    Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 38. East northeast wind around 6 mph.

    Low: 38 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 62. East southeast wind around 6 mph.

    High: 62 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 43. Light east southeast wind.

    Low: 43 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 73. Light south wind becoming south southwest 5 to 9 mph in the morning.

    High: 73 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 59. South wind 7 to 10 mph, with gusts as high as 18 mph.

    Low: 59 °F

    Partly Cloudy

  • Thursday

    Thursday: Sunny, with a high near 85. South southwest wind 10 to 14 mph, with gusts as high as 21 mph.

    High: 85 °F

    Sunny

Detailed Forecast

This Afternoon
A 10 percent chance of showers and thunderstorms after 5pm. Sunny, with a high near 86. South southwest wind 10 to 14 mph, with gusts as high as 21 mph.
Tonight
A chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 11pm. Mostly cloudy, then gradually becoming clear, with a low around 35. North wind 14 to 18 mph, with gusts as high as 29 mph. Chance of precipitation is 30%.
Monday
Sunny, with a high near 55. North northeast wind around 11 mph, with gusts as high as 20 mph.
Monday Night
Mostly cloudy, with a low around 38. East northeast wind around 6 mph.
Tuesday
Mostly sunny, with a high near 62. East southeast wind around 6 mph.
Tuesday Night
Partly cloudy, with a low around 43. Light east southeast wind.
Wednesday
Mostly sunny, with a high near 73. Light south wind becoming south southwest 5 to 9 mph in the morning.
Wednesday Night
Partly cloudy, with a low around 59. South wind 7 to 10 mph, with gusts as high as 18 mph.
Thursday
Sunny, with a high near 85. South southwest wind 10 to 14 mph, with gusts as high as 21 mph.
Thursday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 42. South southwest wind around 14 mph becoming north after midnight. Winds could gust as high as 23 mph.
Friday
A chance of showers. Partly sunny, with a high near 53. North wind around 14 mph, with gusts as high as 23 mph.
Friday Night
A slight chance of showers. Partly cloudy, with a low around 32. North wind 7 to 10 mph, with gusts as high as 18 mph.
Saturday
Sunny, with a high near 57. East wind around 7 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:
1:26 pm CDT Mar 22, 2026
Forecast Valid:
1pm CDT Mar 22, 2026-6pm CDT Mar 28, 2026
 
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Additional Resources

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