Jamestown Weather Forecast

    • 59
    • 78

    Chance Rain Showers

    • 51
    • 75

    Chance Rain Showers

    • 49
    • 62

    Rain Showers Likely

    • 54
    • 71

    Chance Thunderstorms

    • 51
    • 66

    Rain Showers Likely

    • 49
    • 68

    Chance Thunderstorms

    • 47
    • 65

    Slight Chance Thunderstorms

Today 13 Sep Larimer and Boulder Counties Between 6000 and 9000 Feet

Mostly cloudy. Chance of Showers and slight chance of Thunderstorms early in the Afternoon, then a chance of Thunderstorms late in the afternoon. Highs 74 to 84. South Winds 10 to 15 Mph with Gusts up to 20 Mph. Chance of rain 50 percent.

Tonight 13 Sep Larimer and Boulder Counties Between 6000 and 9000 Feet

Mostly cloudy. Slight chance of Thunderstorms in the evening. Chance of Showers through the night. Lows 51 to 61. Chance of rain 40 percent.

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Jamestown Temperature Statistics

September Temperature

Boulder Municipal Airport (9.9 miles)

  • Lowest 10 September, 2026

    53.6 °F

  • Average September

    74.5 °F

  • Highest 4 September, 2026

    95 °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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