Simpson Lake Weather Forecast

    • 48
    • 66

    Slight Chance Rain Showers

    • 45
    • 64

    Chance Rain Showers

    • 46
    • 74

    Mostly Sunny

    • 49
    • 79

    Mostly Sunny

    • 50
    • 78

    Mostly Sunny

    • 49
    • 77

    Mostly Sunny

    • 49
    • 78

    Mostly Sunny

Today 14 Sep Okanogan Highlands

Partly cloudy. Highs in the 60s.

Tonight 14 Sep Okanogan Highlands

Mostly cloudy. A chance of rain Showers. Patchy fog overnight. Lows in the mid to upper 40s. Chance of precipitation 50 percent. Rainfall Amounts less than a tenth of an inch.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Simpson Lake Temperature Statistics

September Temperature

Deer Park, Deer Park Airport (47.2 miles)

  • Lowest 5 September, 2026

    40.6 °F

  • Average September

    59.4 °F

  • Highest 1 September, 2026

    81.6 °F

Climate (2021–2026)

Deer Park, Deer Park Airport (47.2 miles)

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  • Average Low 2021–2026

    35.7 °F

  • Average 2021–2026

    48.3 °F

  • Average High 2021–2026

    60.1 °F
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