Ontario Weather Forecast

    • 50
    • 80

    Decreasing Clouds

    • 45
    • 69

    Rain Showers Likely

    • 57
    • 72

    Rain Showers

    • 50
    • 72

    Chance Rain Showers

    • 51
    • 69

    Chance Rain Showers

    • 50
    • 72

    Slight Chance Thunderstorms

Today 12 Sep Vernon

Mostly sunny. Highs in the upper 70s. West Winds 5 to 10 Mph, becoming northwest in the afternoon.

Tonight 12 Sep Vernon

Mostly clear in the Evening, then becoming partly cloudy. Cooler. Less humid with Lows in the lower 50s. Light Winds.

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  • Temperature Real-Time

Ontario Temperature Statistics

September Temperature

Sparta, Sparta / Fort McCoy Airport (17.4 miles)

  • Lowest 9 September, 2026

    55.6 °F

  • Average September

    73.9 °F

  • Highest 1 September, 2026

    91 °F

Climate (2021–2026)

Sparta, Sparta / Fort McCoy Airport (17.4 miles)

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  • Average Low 2021–2026

    35.3 °F

  • Average 2021–2026

    47.8 °F

  • Average High 2021–2026

    58.5 °F
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