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Hazardous Weather Conditions

Current conditions at

Southern Illinois Airport (KMDH)

Lat: 37.78°NLon: 89.25°WElev: 400ft.

Overcast

67°F

19°C

Humidity 87%
Wind Speed SW 13 mph
Barometer 29.91 in (1012.6 mb)
Dewpoint 63°F (17°C)
Visibility 10.00 mi
Last update 10 Mar 12:52 am CDT
Extended Forecast for

Saint Johns IL

  • Overnight

    Overnight: Mostly cloudy, with a low around 62. South southwest wind around 10 mph, with gusts as high as 21 mph.

    Low: 62 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 78. South southwest wind 8 to 17 mph, with gusts as high as 26 mph.

    High: 78 °F

    Mostly Cloudy

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 5am. Cloudy, with a low around 65. South southwest wind 15 to 17 mph, with gusts as high as 28 mph. Chance of precipitation is 60%.

    Low: 65 °F

    Slight Chance
    T-storms then
    Showers
    Likely

  • Wednesday

    Wednesday: Showers and thunderstorms before 1pm, then showers likely and possibly a thunderstorm between 1pm and 4pm, then showers likely after 4pm. High near 70. Breezy, with a south southwest wind 15 to 21 mph becoming northwest in the afternoon. Winds could gust as high as 29 mph. Chance of precipitation is 90%.

    High: 70 °F

    Showers and
    Breezy

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers before 7pm. Mostly cloudy, with a low around 34. Breezy, with a north northwest wind 15 to 20 mph decreasing to 9 to 14 mph after midnight. Winds could gust as high as 29 mph.

    Low: 34 °F

    Chance
    Showers and
    Breezy then
    Mostly Cloudy

  • Thursday

    Thursday: Sunny, with a high near 53. North northwest wind around 6 mph becoming west southwest in the afternoon.

    High: 53 °F

    Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 42. South wind 6 to 15 mph, with gusts as high as 25 mph.

    Low: 42 °F

    Partly Cloudy

  • Friday

    Friday: Mostly cloudy, with a high near 65. Southwest wind 9 to 14 mph, with gusts as high as 24 mph.

    High: 65 °F

    Mostly Cloudy

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 41. North northwest wind around 6 mph becoming east after midnight.

    Low: 41 °F

    Mostly Cloudy

Detailed Forecast

Overnight
Mostly cloudy, with a low around 62. South southwest wind around 10 mph, with gusts as high as 21 mph.
Tuesday
Mostly cloudy, with a high near 78. South southwest wind 8 to 17 mph, with gusts as high as 26 mph.
Tuesday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 5am. Cloudy, with a low around 65. South southwest wind 15 to 17 mph, with gusts as high as 28 mph. Chance of precipitation is 60%.
Wednesday
Showers and thunderstorms before 1pm, then showers likely and possibly a thunderstorm between 1pm and 4pm, then showers likely after 4pm. High near 70. Breezy, with a south southwest wind 15 to 21 mph becoming northwest in the afternoon. Winds could gust as high as 29 mph. Chance of precipitation is 90%.
Wednesday Night
A 30 percent chance of showers before 7pm. Mostly cloudy, with a low around 34. Breezy, with a north northwest wind 15 to 20 mph decreasing to 9 to 14 mph after midnight. Winds could gust as high as 29 mph.
Thursday
Sunny, with a high near 53. North northwest wind around 6 mph becoming west southwest in the afternoon.
Thursday Night
Partly cloudy, with a low around 42. South wind 6 to 15 mph, with gusts as high as 25 mph.
Friday
Mostly cloudy, with a high near 65. Southwest wind 9 to 14 mph, with gusts as high as 24 mph.
Friday Night
Mostly cloudy, with a low around 41. North northwest wind around 6 mph becoming east after midnight.
Saturday
Mostly sunny, with a high near 69. East wind 7 to 11 mph becoming south in the afternoon. Winds could gust as high as 20 mph.
Saturday Night
Mostly clear, with a low around 52. South southwest wind 10 to 14 mph, with gusts as high as 24 mph.
Sunday
A chance of showers. Partly sunny, with a high near 66. South southwest wind 14 to 18 mph becoming west northwest in the afternoon. Winds could gust as high as 28 mph.
Sunday Night
A chance of rain and snow showers. Partly cloudy, with a low around 30. Northwest wind 14 to 18 mph, with gusts as high as 25 mph.
Monday
Mostly sunny, with a high near 44. North northwest wind 10 to 13 mph, with gusts as high as 20 mph.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Saint Johns IL
 38.03°N 89.24°W
Last Update:
12:01 am CDT Mar 10, 2026
Forecast Valid:
1am CDT Mar 10, 2026-6pm CDT Mar 16, 2026
 
Forecast Discussion
 
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Additional Resources

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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