Janesville Weather Forecast

    • 19
    • 40

    Chance Rain/Snow

    • 9
    • 23

    Mostly Cloudy

    • 9
    • 23

    Partly Sunny

    • 5
    • 16

    Mostly Sunny

    • 18
    • 26

    Partly Sunny

    • 18
    • 37

    Partly Sunny

Today 16 Jan Cumberland

Mostly cloudy with a chance of snow and rain. Little or no additional snow accumulation. Not as cool with Highs around 40. West Winds 10 to 15 Mph with Gusts up to 25 Mph. Chance of precipitation 40 percent.

Tonight 16 Jan Cumberland

Snow. Snow accumulation around an inch. Lows in the lower 20s. Temperature rising into the upper 20s. South Winds 10 to 15 Mph with Gusts up to 25 Mph. Chance of snow 80 percent.

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  • Temperature Real-Time

Janesville Temperature Statistics

January Temperature

Mattoon / Charleston, Coles County Memorial Airport (6.8 miles)

  • Lowest 11 January, 2026

    21 °F

  • Average January

    37.5 °F

  • Highest 8 January, 2026

    64 °F

Climate (2021–Present)

Mattoon / Charleston, Coles County Memorial Airport (6.8 miles)

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  • Average Low 2021–2026

    45.8 °F

  • Average 2021–2026

    55.2 °F

  • Average High 2021–2026

    64.6 °F
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