Great Falls Weather Forecast

    • 27
    • 53

    Decreasing Clouds

    • 40
    • 64

    Chance Rain

    • 37
    • 62

    Rain Likely

    • 41
    • 65

    Partly Sunny

    • 43
    • 70

    Partly Sunny

    • 47
    • 76

    Partly Sunny

Today 18 May Cascade County below 5000ft

Not as cool. Mostly sunny. Patchy fog early in the morning. Highs 48 to 54. Northwest Winds up to 10 Mph shifting to the northeast in the afternoon.

Tonight 18 May Cascade County below 5000ft

Mostly clear. Lows in the upper 20s. South Winds 5 to 10 Mph.

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Great Falls Temperature Statistics

May Temperature

Great Falls, Great Falls International Airport (3.7 miles)

  • Lowest 6 May, 2026

    23.6 °F

  • Average May

    54.5 °F

  • Highest 13 May, 2026

    89.7 °F

Climate (2021–Present)

Great Falls, Great Falls International Airport (3.7 miles)

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  • Average Low 2021–2026

    34.4 °F

  • Average 2021–2026

    47 °F

  • Average High 2021–2026

    59.2 °F
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