Lake Mattoon Weather Forecast

    • 57
    • 67

    Mostly Cloudy

    • 57
    • 74

    Mostly Cloudy

    • 52
    • 74

    Partly Sunny

    • 54
    • 72

    Mostly Cloudy

    • 52
    • 74

    Partly Sunny

    • 55
    • 78

    Mostly Sunny

    • 62
    • 83

    Rain Showers Likely

Today 23 Sep Shelby

Mostly cloudy in the Morning, then becoming partly sunny. A chance of Showers. Highs in the upper 70s. Chance of rain 50 percent.

Tonight 23 Sep Shelby

Cloudy. Lows in the upper 50s. Northeast Winds 5 to 10 Mph.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Lake Mattoon Temperature Statistics

September Temperature

Mattoon / Charleston, Coles County Memorial Airport (13 miles)

  • Lowest 14 September, 2026

    54.6 °F

  • Average September

    79.1 °F

  • Highest 2 September, 2026

    97.6 °F

Climate (2021–2026)

Mattoon / Charleston, Coles County Memorial Airport (13 miles)

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  • Average Low 2021–2026

    45.9 °F

  • Average 2021–2026

    55.5 °F

  • Average High 2021–2026

    65.1 °F
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