Jeffris Park Weather Forecast

    • 61
    • 85

    Partly Sunny

    • 61
    • 82

    Chance Rain Showers

    • 61
    • 78

    Chance Rain Showers

    • 61
    • 76

    Chance Thunderstorms

    • 59
    • 77

    Chance Rain Showers

    • 55
    • 75

    Slight Chance Thunderstorms

Today 18 Sep Rock

Mostly sunny with isolated light Showers. Highs in the mid 80s. Southeast Winds up to 5 Mph. Chance of Showers 20 percent.

Tonight 18 Sep Rock

Partly cloudy through around midnight then becoming mostly cloudy. Slight chance of Thunderstorms and isolated light Showers in the evening. Isolated light Showers after midnight. Slight chance of Thunderstorms early in the morning. Lows in the lower 60s. East Winds 5 to 10 Mph. Chance of precipitation 20 percent.

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Jeffris Park Temperature Statistics

September Temperature

Janesville-Rock County (3.1 miles)

  • Lowest 7 September, 2025

    39.2 °F

  • Average September

    59.4 °F

  • Highest 14 September, 2025

    84.2 °F

Climate (2020–Present)

Janesville-Rock County (3.1 miles)

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  • Average Low 2020–2025

    40.4 °F

  • Average 2020–2025

    48.7 °F

  • Average High 2020–2025

    60.3 °F
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