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.

Fog/Mist

34°F

1°C

Humidity 100%
Wind Speed Calm
Barometer 29.87 in (1011.7 mb)
Dewpoint 34°F (1°C)
Visibility 2.50 mi
Last update 7 Jan 2:53 am CST
Extended Forecast for

Sullivan IL

  • Overnight

    Overnight: Patchy fog after 4am. Otherwise, mostly cloudy, with a low around 33. West northwest wind 3 to 5 mph.

    Low: 33 °F

    Patchy Fog

  • Wednesday

    Wednesday: Patchy fog before 10am. Otherwise, mostly cloudy through mid morning, then gradual clearing, with a high near 53. Calm wind becoming south southwest 5 to 8 mph in the morning.

    High: 53 °F

    Patchy Fog
    then Sunny

  • Wednesday Night

    Wednesday Night: Increasing clouds, with a low around 40. South wind 8 to 10 mph, with gusts as high as 18 mph.

    Low: 40 °F

    Increasing
    Clouds

  • Thursday

    Thursday: Rain likely before 2pm, then rain after 4pm. High near 61. Breezy, with a south southeast wind 10 to 15 mph increasing to 16 to 21 mph in the afternoon. Winds could gust as high as 31 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 61 °F

    Mostly Cloudy
    then Rain and
    Breezy

  • Thursday Night

    Thursday Night: Rain, mainly before midnight. Low around 51. Breezy, with a south southwest wind 15 to 22 mph, with gusts as high as 32 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 51 °F

    Breezy. Rain
    then Chance
    Rain

  • Friday

    Friday: Partly sunny, with a high near 57. Southwest wind 7 to 13 mph becoming north in the afternoon. Winds could gust as high as 21 mph.

    High: 57 °F

    Partly Sunny

  • Friday Night

    Friday Night: A 50 percent chance of rain after midnight. Mostly cloudy, with a low around 38. North northeast wind 6 to 8 mph.

    Low: 38 °F

    Mostly Cloudy
    then Chance
    Rain

  • Saturday

    Saturday: A chance of rain before noon, then a chance of rain and snow. Mostly cloudy, with a high near 44. Chance of precipitation is 40%.

    High: 44 °F

    Chance Rain
    then Chance
    Rain/Snow

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 22.

    Low: 22 °F

    Mostly Cloudy

Detailed Forecast

Overnight
Patchy fog after 4am. Otherwise, mostly cloudy, with a low around 33. West northwest wind 3 to 5 mph.
Wednesday
Patchy fog before 10am. Otherwise, mostly cloudy through mid morning, then gradual clearing, with a high near 53. Calm wind becoming south southwest 5 to 8 mph in the morning.
Wednesday Night
Increasing clouds, with a low around 40. South wind 8 to 10 mph, with gusts as high as 18 mph.
Thursday
Rain likely before 2pm, then rain after 4pm. High near 61. Breezy, with a south southeast wind 10 to 15 mph increasing to 16 to 21 mph in the afternoon. Winds could gust as high as 31 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Thursday Night
Rain, mainly before midnight. Low around 51. Breezy, with a south southwest wind 15 to 22 mph, with gusts as high as 32 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Friday
Partly sunny, with a high near 57. Southwest wind 7 to 13 mph becoming north in the afternoon. Winds could gust as high as 21 mph.
Friday Night
A 50 percent chance of rain after midnight. Mostly cloudy, with a low around 38. North northeast wind 6 to 8 mph.
Saturday
A chance of rain before noon, then a chance of rain and snow. Mostly cloudy, with a high near 44. Chance of precipitation is 40%.
Saturday Night
Mostly cloudy, with a low around 22.
Sunday
Mostly sunny, with a high near 30.
Sunday Night
Mostly clear, with a low around 19.
Monday
Sunny, with a high near 40.
Monday Night
Partly cloudy, with a low around 27.
Tuesday
Mostly sunny, with a high near 45.
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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:
3:26 am CST Jan 7, 2026
Forecast Valid:
3am CST Jan 7, 2026-6pm CST Jan 13, 2026
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation