Jamestown Weather Forecast

    • 49
    • 72

    Rain Showers Likely

    • 46
    • 67

    Rain Showers Likely

    • 44
    • 63

    Chance Thunderstorms

    • 46
    • 65

    Slight Chance Thunderstorms

    • 47
    • 66

    Chance Thunderstorms

    • 48
    • 69

    Slight Chance Thunderstorms

Today 18 Sep Larimer and Boulder Counties Between 6000 and 9000 Feet

Showers likely and chance of Thunderstorms in the afternoon. Highs 67 to 77. Chance of rain 70 percent.

Tonight 18 Sep Larimer and Boulder Counties Between 6000 and 9000 Feet

Mostly cloudy with a chance of Showers and slight chance of Thunderstorms in the Evening, then partly cloudy after midnight. Lows 42 to 52. Chance of rain 40 percent.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Jamestown Temperature Statistics

September Temperature

Boulder Municipal Airport (9.9 miles)

  • Lowest 10 September, 2026

    53.6 °F

  • Average September

    73.3 °F

  • Highest 13 September, 2026

    96.8 °F

Climate (2021–2026)

Boulder Municipal Airport (9.9 miles)

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  • Average Low 2021–2026

    41.3 °F

  • Average 2021–2026

    53.7 °F

  • Average High 2021–2026

    66.4 °F
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