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.

Fog/Mist

59°F

15°C

Humidity 100%
Wind Speed Calm
Barometer 30.11 in (1019.5 mb)
Dewpoint 59°F (15°C)
Visibility 6.00 mi
Last update 23 Jun 3:52 am CDT
Extended Forecast for

Alto Pass IL

  • Today

    Today: Sunny, with a high near 81. North northeast wind 3 to 5 mph.

    High: 81 °F

    Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 62. Calm wind.

    Low: 62 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 82. Calm wind becoming south 5 to 7 mph in the morning.

    High: 82 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers after 1am. Partly cloudy, with a low around 67. South wind around 5 mph becoming calm in the evening.

    Low: 67 °F

    Mostly Clear
    then Chance
    Showers

  • Thursday

    Thursday: A slight chance of showers before 10am, then a slight chance of showers and thunderstorms between 10am and 1pm, then showers likely and possibly a thunderstorm after 1pm. Mostly sunny, with a high near 84. Calm wind becoming south around 6 mph in the afternoon. Chance of precipitation is 60%.

    High: 84 °F

    Slight Chance
    T-storms then
    Showers
    Likely

  • Thursday Night

    Thursday Night: Showers and thunderstorms likely, then showers and possibly a thunderstorm after 10pm. Low around 70. South wind around 5 mph becoming calm in the evening. Chance of precipitation is 80%.

    Low: 70 °F

    T-storms
    Likely then
    Showers

  • Friday

    Friday: Showers likely and possibly a thunderstorm. Partly sunny, with a high near 84. Southwest wind 5 to 9 mph. Chance of precipitation is 70%.

    High: 84 °F

    Showers
    Likely

  • Friday Night

    Friday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 72. South southwest wind 5 to 8 mph.

    Low: 72 °F

    Showers
    Likely

  • Saturday

    Saturday: A chance of showers and thunderstorms, mainly before 1pm. Partly sunny, with a high near 87. Southwest wind 6 to 9 mph.

    High: 87 °F

    Chance
    Showers

Detailed Forecast

Today
Sunny, with a high near 81. North northeast wind 3 to 5 mph.
Tonight
Partly cloudy, with a low around 62. Calm wind.
Wednesday
Mostly sunny, with a high near 82. Calm wind becoming south 5 to 7 mph in the morning.
Wednesday Night
A 30 percent chance of showers after 1am. Partly cloudy, with a low around 67. South wind around 5 mph becoming calm in the evening.
Thursday
A slight chance of showers before 10am, then a slight chance of showers and thunderstorms between 10am and 1pm, then showers likely and possibly a thunderstorm after 1pm. Mostly sunny, with a high near 84. Calm wind becoming south around 6 mph in the afternoon. Chance of precipitation is 60%.
Thursday Night
Showers and thunderstorms likely, then showers and possibly a thunderstorm after 10pm. Low around 70. South wind around 5 mph becoming calm in the evening. Chance of precipitation is 80%.
Friday
Showers likely and possibly a thunderstorm. Partly sunny, with a high near 84. Southwest wind 5 to 9 mph. Chance of precipitation is 70%.
Friday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 72. South southwest wind 5 to 8 mph.
Saturday
A chance of showers and thunderstorms, mainly before 1pm. Partly sunny, with a high near 87. Southwest wind 6 to 9 mph.
Saturday Night
A slight chance of showers and thunderstorms. Partly cloudy, with a low around 74. South wind 6 to 8 mph.
Sunday
Sunny, with a high near 90. South southwest wind 7 to 14 mph, with gusts as high as 24 mph.
Sunday Night
Clear, with a low around 76. South wind 7 to 13 mph, with gusts as high as 21 mph.
Monday
Sunny, with a high near 92. South southwest wind 7 to 13 mph, with gusts as high as 21 mph.
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ABOUT THIS FORECAST

 
Point Forecast:
Alto Pass IL
 37.57°N 89.32°W
Last Update:
3:16 am CDT Jun 23, 2026
Forecast Valid:
4am CDT Jun 23, 2026-6pm CDT Jun 29, 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