Cornelius Weather Forecast

    • 52
    • 78

    Sunny

    • 51
    • 83

    Sunny

    • 57
    • 80

    Rain Likely

    • 49
    • 73

    Slight Chance Rain

    • 53
    • 78

    Mostly Sunny

    • 57
    • 82

    Slight Chance Rain

Today 18 Sep Tualatin Valley

Sunny. Highs in the upper 70s. North wind 5 to 10 Mph.

Tonight 18 Sep Tualatin Valley

Clear. Lows in the lower 50s. Northwest wind 5 to 10 Mph.

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Cornelius Temperature Statistics

September Temperature

Portland-Hillsboro Airport (5 miles)

  • Lowest 15 September, 2025

    44.1 °F

  • Average September

    67.3 °F

  • Highest 2 September, 2025

    91 °F

Climate (2020–Present)

Portland-Hillsboro Airport (5 miles)

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  • Average Low 2020–2025

    43.2 °F

  • Average 2020–2025

    53.6 °F

  • Average High 2020–2025

    64.4 °F
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