Mammoth Weather Forecast

    • 43
    • 78

    Sunny

    • 47
    • 84

    Sunny

    • 49
    • 86

    Mostly Sunny

    • 52
    • 85

    Mostly Cloudy

    • 49
    • 79

    Mostly Cloudy

    • 48
    • 79

    Chance Rain Showers

    • 46
    • 77

    Partly Sunny

Today 15 Sep Northeast Siskiyou and Northwest Modoc Counties

Sunny. Highs in the mid 70s to lower 80s. East Winds 5 to 10 Mph.

Tonight 15 Sep Northeast Siskiyou and Northwest Modoc Counties

Clear. Lows in the lower to mid 40s. North Winds around 5 Mph shifting to the east after midnight.

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  • Temperature Real-Time

Mammoth Temperature Statistics

September Temperature

Klamath Falls International Airport (34.2 miles)

  • Lowest 12 September, 2025

    41 °F

  • Average September

    61.9 °F

  • Highest 2 September, 2025

    89.1 °F

Climate (2020–Present)

Klamath Falls International Airport (34.2 miles)

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  • Average Low 2020–2025

    33.8 °F

  • Average 2020–2025

    48.6 °F

  • Average High 2020–2025

    63.1 °F
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