Janesville Weather Forecast

    • 1
    • 10

    Cold

    • 8
    • 11

    Snow

    • -1
    • 14

    Snow

    • -1
    • 10

    Cold

    • 10
    • 24

    Mostly Cloudy

    • 1
    • 20

    Partly Sunny

Today 23 Jan Cumberland

Partly sunny. Much cooler with Highs around 11. North Winds 15 to 20 Mph with Gusts up to 30 Mph. Wind chill Values as low as 15 below.

Tonight 23 Jan Cumberland

Mostly cloudy. Cooler with Lows around 5 above. North Winds 15 to 20 Mph. Wind chill Values as low as 6 below.

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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 19 January, 2026

    7 °F

  • Average January

    32 °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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