Lewis Lake Weather Forecast

    • 33
    • 61

    Increasing Clouds

    • 35
    • 61

    Chance Rain Showers

    • 34
    • 61

    Mostly Sunny

    • 36
    • 67

    Mostly Sunny

    • 36
    • 65

    Mostly Sunny

    • 33
    • 61

    Partly Sunny

Today 21 Sep Yellowstone National Park

Areas of fog this morning. Mostly sunny. Highs in the lower 60s.

Tonight 21 Sep Yellowstone National Park

Mostly clear. Lows in the mid 30s.

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Lewis Lake Temperature Statistics

September Temperature

Yellowstone Lake (19.3 miles)

  • Lowest 15 September, 2026

    25.6 °F

  • Average September

    48.7 °F

  • Highest 6 September, 2026

    72.6 °F

Climate (2021–2026)

Yellowstone Lake (19.3 miles)

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  • Average Low 2021–2026

    23.1 °F

  • Average 2021–2026

    35.8 °F

  • Average High 2021–2026

    48.6 °F
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