National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

Southern Illinois Airport (KMDH)

Lat: 37.78°NLon: 89.25°WElev: 400ft.

Fair

56°F

13°C

Humidity 30%
Wind Speed SW 14 mph
Barometer 30.18 in (1022.1 mb)
Dewpoint 25°F (-4°C)
Visibility 10.00 mi
Last update 13 Feb 12:52 pm CST
Extended Forecast for

Saint Johns IL

  • This Afternoon

    This Afternoon: Sunny, with a high near 57. South wind 5 to 8 mph.

    High: 57 °F

    Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 38. Light south wind.

    Low: 38 °F

    Increasing
    Clouds

  • Saturday

    Saturday: Showers, mainly after noon. High near 52. Calm wind becoming south southeast around 6 mph in the afternoon. Chance of precipitation is 80%.

    High: 52 °F

    Chance
    Showers then
    Showers

  • Saturday Night

    Saturday Night: Showers. Low around 46. East wind around 7 mph. Chance of precipitation is 100%.

    Low: 46 °F

    Showers

  • Sunday

    Sunday: A 30 percent chance of showers before noon. Mostly cloudy, with a high near 55. North northeast wind 6 to 10 mph.

    High: 55 °F

    Chance
    Showers then
    Partly Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 39. North northeast wind around 5 mph becoming calm in the evening.

    Low: 39 °F

    Mostly Clear

  • Washington's Birthday

    Washington's Birthday: Mostly sunny, with a high near 61. Calm wind becoming south around 6 mph in the afternoon.

    High: 61 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 44. South wind around 6 mph.

    Low: 44 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 64. South wind 6 to 14 mph, with gusts as high as 22 mph.

    High: 64 °F

    Mostly Cloudy

Detailed Forecast

This Afternoon
Sunny, with a high near 57. South wind 5 to 8 mph.
Tonight
Increasing clouds, with a low around 38. Light south wind.
Saturday
Showers, mainly after noon. High near 52. Calm wind becoming south southeast around 6 mph in the afternoon. Chance of precipitation is 80%.
Saturday Night
Showers. Low around 46. East wind around 7 mph. Chance of precipitation is 100%.
Sunday
A 30 percent chance of showers before noon. Mostly cloudy, with a high near 55. North northeast wind 6 to 10 mph.
Sunday Night
Mostly clear, with a low around 39. North northeast wind around 5 mph becoming calm in the evening.
Washington's Birthday
Mostly sunny, with a high near 61. Calm wind becoming south around 6 mph in the afternoon.
Monday Night
Mostly cloudy, with a low around 44. South wind around 6 mph.
Tuesday
Mostly cloudy, with a high near 64. South wind 6 to 14 mph, with gusts as high as 22 mph.
Tuesday Night
Mostly cloudy, with a low around 55. South southwest wind 13 to 15 mph, with gusts as high as 23 mph.
Wednesday
Partly sunny, with a high near 71. Southwest wind 9 to 14 mph, with gusts as high as 22 mph.
Wednesday Night
Mostly cloudy, with a low around 50. South southwest wind around 8 mph.
Thursday
A chance of showers. Partly sunny, with a high near 68. South southwest wind 8 to 13 mph, with gusts as high as 22 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:
12:21 pm CST Feb 13, 2026
Forecast Valid:
1pm CST Feb 13, 2026-6pm CST Feb 19, 2026
 
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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