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

Mattoon / Charleston, Coles County Memorial Airport (KMTO)

Lat: 39.48°NLon: 88.28°WElev: 722ft.

A Few Clouds

75°F

24°C

Humidity 54%
Wind Speed W 9 mph
Barometer 29.89 in (1011.6 mb)
Dewpoint 57°F (14°C)
Visibility 10.00 mi
Last update 16 Apr 5:53 pm CDT
Extended Forecast for

Sullivan IL

  • Tonight

    Tonight: Clear, with a low around 55. West wind 5 to 8 mph becoming south after midnight. Winds could gust as high as 16 mph.

    Low: 55 °F

    Clear

  • Friday

    Friday: Mostly sunny, with a high near 81. South wind 6 to 16 mph, with gusts as high as 29 mph.

    High: 81 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Showers and thunderstorms likely, then showers and possibly a thunderstorm after 1am. Low around 51. South wind around 15 mph, with gusts as high as 28 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.

    Low: 51 °F

    Chance
    T-storms then
    T-storms

  • Saturday

    Saturday: Showers likely, mainly before 1pm. Mostly cloudy, then gradually becoming sunny, with a high near 60. West northwest wind 15 to 18 mph, with gusts as high as 29 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 60 °F

    Showers
    Likely

  • Saturday Night

    Saturday Night: Patchy frost after 3am. Otherwise, mostly clear, with a low around 36. West northwest wind 8 to 14 mph, with gusts as high as 22 mph.

    Low: 36 °F

    Mostly Clear
    then Patchy
    Frost

  • Sunday

    Sunday: Patchy frost before 8am. Otherwise, sunny, with a high near 58. West northwest wind 8 to 17 mph, with gusts as high as 28 mph.

    High: 58 °F

    Patchy Frost
    then Sunny

  • Sunday Night

    Sunday Night: Patchy frost after 3am. Otherwise, mostly clear, with a low around 35. North northwest wind 5 to 9 mph becoming east after midnight. Winds could gust as high as 16 mph.

    Low: 35 °F

    Mostly Clear
    then Patchy
    Frost

  • Monday

    Monday: Patchy frost before 8am. Otherwise, sunny, with a high near 64.

    High: 64 °F

    Patchy Frost
    then Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 50.

    Low: 50 °F

    Mostly Clear

Detailed Forecast

Tonight
Clear, with a low around 55. West wind 5 to 8 mph becoming south after midnight. Winds could gust as high as 16 mph.
Friday
Mostly sunny, with a high near 81. South wind 6 to 16 mph, with gusts as high as 29 mph.
Friday Night
Showers and thunderstorms likely, then showers and possibly a thunderstorm after 1am. Low around 51. South wind around 15 mph, with gusts as high as 28 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.
Saturday
Showers likely, mainly before 1pm. Mostly cloudy, then gradually becoming sunny, with a high near 60. West northwest wind 15 to 18 mph, with gusts as high as 29 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.
Saturday Night
Patchy frost after 3am. Otherwise, mostly clear, with a low around 36. West northwest wind 8 to 14 mph, with gusts as high as 22 mph.
Sunday
Patchy frost before 8am. Otherwise, sunny, with a high near 58. West northwest wind 8 to 17 mph, with gusts as high as 28 mph.
Sunday Night
Patchy frost after 3am. Otherwise, mostly clear, with a low around 35. North northwest wind 5 to 9 mph becoming east after midnight. Winds could gust as high as 16 mph.
Monday
Patchy frost before 8am. Otherwise, sunny, with a high near 64.
Monday Night
Mostly clear, with a low around 50.
Tuesday
Mostly sunny, with a high near 75.
Tuesday Night
Partly cloudy, with a low around 54.
Wednesday
Mostly sunny, with a high near 76.
Wednesday Night
Partly cloudy, with a low around 52.
Thursday
Mostly sunny, with a high near 75.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Sullivan IL
 39.59°N 88.61°W (Elev. 669 ft)
Last Update:
6:36 pm CDT Apr 16, 2026
Forecast Valid:
6pm CDT Apr 16, 2026-6pm CDT Apr 23, 2026
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation