Big Arm Weather Forecast

    • 41
    • 59

    Slight Chance Thunderstorms

    • 44
    • 63

    Chance Rain Showers

    • 43
    • 64

    Rain Showers Likely

    • 46
    • 66

    Mostly Cloudy

    • 47
    • 68

    Chance Rain

    • 48
    • 72

    Partly Sunny

Today 18 May Flathead/Mission Valleys

Mostly sunny. Widespread frost early in the morning. Chance of rain Showers and a slight chance of Thunderstorms in the afternoon. Chance of precipitation 30 percent. Highs in the mid 50s to lower 60s.

Tonight 18 May Flathead/Mission Valleys

Partly cloudy. A 20 percent chance of rain in the evening. Areas of frost after midnight. Lows in the 30s.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Big Arm Temperature Statistics

May Temperature

Kalispell, Glacier Park International Airport (34.8 miles)

  • Lowest 6 May, 2026

    29.6 °F

  • Average May

    53.8 °F

  • Highest 12 May, 2026

    76.6 °F

Climate (2021–Present)

Kalispell, Glacier Park International Airport (34.8 miles)

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  • Average Low 2021–2026

    33.5 °F

  • Average 2021–2026

    45.5 °F

  • Average High 2021–2026

    57.2 °F
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