Costich Lake Weather Forecast

    • 43
    • 56

    Rain Showers

    • 45
    • 60

    Chance Rain Showers

    • 43
    • 60

    Chance Rain Showers

    • 44
    • 68

    Mostly Sunny

    • 46
    • 74

    Mostly Sunny

    • 47
    • 75

    Mostly Sunny

    • 47
    • 74

    Partly Sunny

Today 13 Sep Kootenai/Cabinet Region

Rain likely in the Morning, then rain Showers likely and a slight chance of Thunderstorms in the afternoon. Patchy fog late in the morning. Chance of precipitation near 100 percent. Highs in the mid 50s to lower 60s.

Tonight 13 Sep Kootenai/Cabinet Region

Chance of rain Showers until early Morning, then rain Showers likely late in the night. Chance of Showers near 100 percent. Lows in the 40s.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Costich Lake Temperature Statistics

September Temperature

Kalispell, Glacier Park International Airport (52.8 miles)

  • Lowest 1 September, 2026

    41.6 °F

  • Average September

    58 °F

  • Highest 1 September, 2026

    84.7 °F

Climate (2021–2026)

Kalispell, Glacier Park International Airport (52.8 miles)

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  • Average Low 2021–2026

    33.4 °F

  • Average 2021–2026

    45.4 °F

  • Average High 2021–2026

    57 °F
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