Johnstown Weather Forecast

    • 56
    • 85

    Mostly Cloudy

    • 56
    • 76

    Chance Rain Showers

    • 51
    • 70

    Chance Rain Showers

    • 48
    • 71

    Chance Rain Showers

    • 44
    • 68

    Mostly Sunny

    • 47
    • 75

    Mostly Sunny

    • 48
    • 79

    Partly Sunny

Today 27 Sep Central and South Weld County

Mostly sunny. Highs in the lower to mid 70s.

Tonight 27 Sep Central and South Weld County

Mostly cloudy. Slight chance of Thunderstorms early in the Evening, then a slight chance of Showers overnight. Lows in the mid to upper 50s. Southeast Winds 10 to 15 Mph with Gusts up to 25 Mph. Chance of rain 20 percent.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Johnstown Temperature Statistics

September Temperature

Fort Collins/Loveland - Northern Colorado Regional Airport (9.3 miles)

  • Lowest 21 September, 2026

    46.9 °F

  • Average September

    69.9 °F

  • Highest 5 September, 2026

    97 °F

Climate (2021–2026)

Fort Collins/Loveland - Northern Colorado Regional Airport (9.3 miles)

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  • Average Low 2021–2026

    38.7 °F

  • Average 2021–2026

    51.9 °F

  • Average High 2021–2026

    66.2 °F
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