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Hazardous Weather Conditions

Current conditions at

Southern Illinois Airport (KMDH)

Lat: 37.78°NLon: 89.25°WElev: 400ft.

A Few Clouds and Breezy

81°F

27°C

Humidity 61%
Wind Speed S 24 G 32 mph
Barometer 29.87 in (1011.3 mb)
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 17 Apr 2:52 pm CDT
Extended Forecast for

Saint Johns IL

  • This Afternoon

    This Afternoon: A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 84. South wind around 15 mph, with gusts as high as 23 mph.

    High: 84 °F

    Slight Chance
    T-storms

  • Tonight

    Tonight: A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 2am. Low around 51. South wind around 14 mph becoming west after midnight. Winds could gust as high as 23 mph. Chance of precipitation is 80%.

    Low: 51 °F

    Slight Chance
    T-storms then
    Showers

  • Saturday

    Saturday: Showers and thunderstorms before 11am, then a slight chance of showers between 11am and 4pm. Temperature falling to around 52 by 9am. West southwest wind 11 to 16 mph becoming north northwest in the afternoon. Winds could gust as high as 24 mph. Chance of precipitation is 80%.

    High: 64 °F⇓

    Showers then
    Slight Chance
    Showers

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 39. North northwest wind 6 to 11 mph becoming light and variable after midnight. Winds could gust as high as 20 mph.

    Low: 39 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 68. Light southwest wind becoming west 8 to 13 mph in the morning. Winds could gust as high as 20 mph.

    High: 68 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 41. West northwest wind around 6 mph becoming light and variable after midnight.

    Low: 41 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 69. East northeast wind 5 to 7 mph becoming south in the afternoon.

    High: 69 °F

    Sunny

  • Monday Night

    Monday Night: Clear, with a low around 51. South wind around 7 mph.

    Low: 51 °F

    Clear

  • Tuesday

    Tuesday: Mostly sunny, with a high near 79. Southwest wind 7 to 14 mph, with gusts as high as 21 mph.

    High: 79 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 84. South wind around 15 mph, with gusts as high as 23 mph.
Tonight
A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 2am. Low around 51. South wind around 14 mph becoming west after midnight. Winds could gust as high as 23 mph. Chance of precipitation is 80%.
Saturday
Showers and thunderstorms before 11am, then a slight chance of showers between 11am and 4pm. Temperature falling to around 52 by 9am. West southwest wind 11 to 16 mph becoming north northwest in the afternoon. Winds could gust as high as 24 mph. Chance of precipitation is 80%.
Saturday Night
Mostly clear, with a low around 39. North northwest wind 6 to 11 mph becoming light and variable after midnight. Winds could gust as high as 20 mph.
Sunday
Sunny, with a high near 68. Light southwest wind becoming west 8 to 13 mph in the morning. Winds could gust as high as 20 mph.
Sunday Night
Mostly clear, with a low around 41. West northwest wind around 6 mph becoming light and variable after midnight.
Monday
Sunny, with a high near 69. East northeast wind 5 to 7 mph becoming south in the afternoon.
Monday Night
Clear, with a low around 51. South wind around 7 mph.
Tuesday
Mostly sunny, with a high near 79. Southwest wind 7 to 14 mph, with gusts as high as 21 mph.
Tuesday Night
A slight chance of showers after 1am. Partly cloudy, with a low around 57. Southwest wind 6 to 9 mph.
Wednesday
Sunny, with a high near 81. Southwest wind 6 to 9 mph.
Wednesday Night
Mostly clear, with a low around 58. South wind around 6 mph.
Thursday
Sunny, with a high near 83. South wind 7 to 13 mph, with gusts as high as 20 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 Apr 17, 2026
Forecast Valid:
3pm CDT Apr 17, 2026-6pm CDT Apr 23, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

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Chance of Precipitation