Johnstown Weather Forecast

    • 55
    • 84

    Slight Chance Thunderstorms

    • 53
    • 88

    Partly Sunny

    • 54
    • 87

    Partly Sunny

    • 54
    • 87

    Partly Sunny

    • 54
    • 87

    Slight Chance Thunderstorms

    • 51
    • 82

    Chance Rain Showers

Today 7 Sep Central and South Weld County

Mostly cloudy. Slight chance of Thunderstorms in the afternoon. Highs in the mid 80s. Chance of precipitation 20 percent.

Tonight 7 Sep Central and South Weld County

Mostly cloudy with a slight chance of Thunderstorms in the Evening, then partly cloudy after midnight. Lows 50 to 56. Chance of precipitation 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 5 September, 2025

    50 °F

  • Average September

    68.2 °F

  • Highest 3 September, 2025

    90 °F

Climate (2020–Present)

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

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  • Average Low 2020–2025

    37.6 °F

  • Average 2020–2025

    50.7 °F

  • Average High 2020–2025

    64.9 °F
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