Janesville Weather Forecast

    • 46
    • 63

    Rain

    • 38
    • 52

    Decreasing Clouds

    • 21
    • 43

    Chance Rain

    • 22
    • 31

    Mostly Sunny

    • 32
    • 42

    Partly Sunny

    • 33
    • 48

    Slight Chance Rain

    • 22
    • 39

    Mostly Cloudy

Today 8 Jan Cumberland

Cloudy with a 50 percent chance of rain. Highs in the mid 60s. South Winds 15 to 20 Mph with Gusts up to 35 Mph.

Tonight 8 Jan Cumberland

Rain with a chance of Thunderstorms early this Evening, then rain likely with a slight chance of Thunderstorms. Some Thunderstorms may produce gusty Winds early this evening. Some Thunderstorms may produce gusty Winds. Breezy with Lows in the upper 40s. Southwest Winds 20 to 25 Mph with Gusts up to 40 Mph. Chance of rain 90 percent.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Janesville Temperature Statistics

January Temperature

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

  • Lowest 4 January, 2026

    21.9 °F

  • Average January

    33.9 °F

  • Highest 6 January, 2026

    54 °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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