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

77°F

25°C

Humidity 79%
Wind Speed NA
Barometer 30.02 in (1015.7 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Heat Index79°F (26°C)
Last update 2 Sep 2:53 am CDT
Extended Forecast for

Sullivan IL

Heat Advisory September 2, 03:49am until September 4, 07:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory September 2, 03:49am until September 4, 07:00pm

    NOW until 7:00pm Fri

    Heat Advisory

  • Overnight

    Low: 71 °F

    Clear

  • Wednesday

    Wednesday: Sunny and hot, with a high near 98. Heat index values as high as 103. Southwest wind 7 to 10 mph, with gusts as high as 17 mph.

    High: 98 °F

    Hot

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 75. South wind 5 to 7 mph.

    Low: 75 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny and hot, with a high near 97. Heat index values as high as 102. Southwest wind 6 to 9 mph.

    High: 97 °F

    Hot

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 75. South southwest wind 3 to 5 mph.

    Low: 75 °F

    Mostly Clear

  • Friday

    Friday: Sunny and hot, with a high near 97. West southwest wind around 6 mph.

    High: 97 °F

    Hot

  • Friday Night

    Friday Night: Partly cloudy, with a low around 73. Calm wind.

    Low: 73 °F

    Partly Cloudy

  • Saturday

    Saturday: A 30 percent chance of showers and thunderstorms before 1pm. Mostly sunny, with a high near 94.

    High: 94 °F

    Chance
    T-storms

Detailed Forecast

Overnight
Clear, with a low around 71. South southwest wind around 7 mph.
Wednesday
Sunny and hot, with a high near 98. Heat index values as high as 103. Southwest wind 7 to 10 mph, with gusts as high as 17 mph.
Wednesday Night
Mostly clear, with a low around 75. South wind 5 to 7 mph.
Thursday
Sunny and hot, with a high near 97. Heat index values as high as 102. Southwest wind 6 to 9 mph.
Thursday Night
Mostly clear, with a low around 75. South southwest wind 3 to 5 mph.
Friday
Sunny and hot, with a high near 97. West southwest wind around 6 mph.
Friday Night
Partly cloudy, with a low around 73. Calm wind.
Saturday
A 30 percent chance of showers and thunderstorms before 1pm. Mostly sunny, with a high near 94.
Saturday Night
Partly cloudy, with a low around 70.
Sunday
Sunny, with a high near 89.
Sunday Night
Partly cloudy, with a low around 66.
Labor Day
Mostly sunny, with a high near 88.
Monday Night
Partly cloudy, with a low around 65.
Tuesday
Mostly sunny, with a high near 89.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Sullivan IL
 39.61°N 88.61°W (Elev. 669 ft)
Last Update:
3:36 am CDT Sep 2, 2026
Forecast Valid:
3am CDT Sep 2, 2026-6pm CDT Sep 8, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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