Johnstown Weather Forecast

    • 65
    • 82

    Mostly Sunny

    • 69
    • 95

    Rain Showers Likely

    • 71
    • 93

    Chance Rain Showers

    • 69
    • 94

    Partly Sunny

    • 68
    • 90

    Slight Chance Thunderstorms

    • 65
    • 89

    Slight Chance Thunderstorms

Today 14 Sep Cumberland

Sunny. Highs in the lower 80s. East Winds around 10 Mph.

Tonight 14 Sep Cumberland

Mostly clear. Lows in the mid 60s. Southeast Winds 5 to 10 Mph.

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  • Temperature Real-Time

Johnstown Temperature Statistics

September Temperature

Mattoon / Charleston, Coles County Memorial Airport (7.5 miles)

  • Lowest 7 September, 2026

    57.7 °F

  • Average September

    79.7 °F

  • Highest 2 September, 2026

    97.6 °F

Climate (2021–2026)

Mattoon / Charleston, Coles County Memorial Airport (7.5 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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