Lewistown Weather Forecast

    • 44
    • 75

    Mostly Sunny

    • 48
    • 79

    Partly Sunny

    • 48
    • 79

    Mostly Sunny

    • 52
    • 83

    Mostly Sunny

    • 45
    • 82

    Slight Chance Rain

    • 39
    • 68

    Slight Chance Rain

Today 21 Sep Fergus County below 4500ft

Mostly sunny. Patchy fog in the morning. Highs in the mid 70s. Southeast Winds 5 to 15 Mph.

Tonight 21 Sep Fergus County below 4500ft

Mostly clear. Lows in the upper 40s. Southeast Winds 5 to 15 Mph with Gusts to around 30 Mph.

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Lewistown Temperature Statistics

September Temperature

Lewistown, Lewistown Municipal Airport (1.2 miles)

  • Lowest 9 September, 2026

    39.7 °F

  • Average September

    61 °F

  • Highest 2 September, 2026

    87.7 °F

Climate (2021–2026)

Lewistown, Lewistown Municipal Airport (1.2 miles)

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  • Average Low 2021–2026

    32.5 °F

  • Average 2021–2026

    44.9 °F

  • Average High 2021–2026

    57 °F
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