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

Hazardous Weather Conditions

Current conditions at

Mattoon / Charleston, Coles County Memorial Airport (KMTO)

Lat: 39.48°NLon: 88.28°WElev: 722ft.

Fair

74°F

23°C

Humidity 85%
Wind Speed S 6 mph
Barometer 30.01 in (1015.5 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Last update 17 Aug 4:53 am CDT
Extended Forecast for

Lerna IL

Heat Advisory August 17, 05:23am until August 17, 08:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 17, 05:23am until August 17, 08:00pm

    NOW until 8:00pm Sun

    Heat Advisory

  • Today

    High: 91 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Tonight

    Tonight: Partly cloudy, with a low around 74. Light and variable wind.

    Low: 74 °F

    Partly Cloudy

  • Monday

    Monday: Sunny, with a high near 91. Heat index values as high as 100. East southeast wind around 5 mph becoming calm in the afternoon.

    High: 91 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 73. Light east southeast wind.

    Low: 73 °F

    Mostly Clear

  • Tuesday

    Tuesday: A chance of showers between 1pm and 4pm, then a chance of showers and thunderstorms after 4pm. Mostly sunny, with a high near 91. Light and variable wind becoming west southwest around 6 mph in the morning. Chance of precipitation is 30%.

    High: 91 °F

    Sunny then
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A 30 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 70. Calm wind becoming north northwest around 5 mph after midnight.

    Low: 70 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: Partly sunny, with a high near 83. North northeast wind 6 to 8 mph.

    High: 83 °F

    Partly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 66.

    Low: 66 °F

    Partly Cloudy

Detailed Forecast

Today
A 20 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 91. Heat index values as high as 102. Light and variable wind.
Tonight
Partly cloudy, with a low around 74. Light and variable wind.
Monday
Sunny, with a high near 91. Heat index values as high as 100. East southeast wind around 5 mph becoming calm in the afternoon.
Monday Night
Mostly clear, with a low around 73. Light east southeast wind.
Tuesday
A chance of showers between 1pm and 4pm, then a chance of showers and thunderstorms after 4pm. Mostly sunny, with a high near 91. Light and variable wind becoming west southwest around 6 mph in the morning. Chance of precipitation is 30%.
Tuesday Night
A 30 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 70. Calm wind becoming north northwest around 5 mph after midnight.
Wednesday
Partly sunny, with a high near 83. North northeast wind 6 to 8 mph.
Wednesday Night
Partly cloudy, with a low around 66.
Thursday
Mostly sunny, with a high near 83.
Thursday Night
Mostly clear, with a low around 64.
Friday
Sunny, with a high near 85.
Friday Night
Mostly clear, with a low around 65.
Saturday
Sunny, with a high near 86.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Lerna IL
 39.42°N 88.25°W (Elev. 712 ft)
Last Update:
4:56 am CDT Aug 17, 2025
Forecast Valid:
5am CDT Aug 17, 2025-6pm CDT Aug 23, 2025
 
Forecast Discussion
 
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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