Helena Valley Regulating Reservoir Weather Forecast

    • 29
    • 56

    Partly Sunny

    • 36
    • 65

    Slight Chance Rain

    • 35
    • 60

    Rain Likely

    • 35
    • 65

    Mostly Cloudy

    • 39
    • 69

    Slight Chance Thunderstorms

    • 43
    • 76

    Partly Sunny

    • 44
    • 79

    Partly Sunny

Today 18 May Helena Valley

Mostly sunny. Highs in the mid 50s. North Winds 5 to 10 Mph.

Tonight 18 May Helena Valley

Partly cloudy. Lows in the upper 20s. West Winds up to 5 Mph shifting to the south after midnight.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Helena Valley Regulating Reservoir Temperature Statistics

May Temperature

Helena Regional Airport (5.6 miles)

  • Lowest 6 May, 2026

    27.6 °F

  • Average May

    55.7 °F

  • Highest 13 May, 2026

    84.7 °F

Climate (2021–Present)

Helena Regional Airport (5.6 miles)

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  • Average Low 2021–2026

    36.5 °F

  • Average 2021–2026

    48.1 °F

  • Average High 2021–2026

    60.1 °F
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