Thornton Weather Forecast

    • 50
    • 72

    Mostly Sunny

    • 55
    • 82

    Partly Sunny

    • 56
    • 82

    Partly Sunny

    • 55
    • 83

    Partly Sunny

    • 49
    • 80

    Mostly Sunny

    • 50
    • 78

    Mostly Sunny

Today 18 Sep North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County

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

Tonight 18 Sep North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County

Mostly clear. Lows near 50.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Thornton Temperature Statistics

September Temperature

Broomfield / Jeffco (6.8 miles)

  • Lowest 6 September, 2025

    48.2 °F

  • Average September

    65.9 °F

  • Highest 10 September, 2025

    91.4 °F

Climate (2020–Present)

Broomfield / Jeffco (6.8 miles)

Take a look at our website widgetsAvailable free! Find Out More

  • Average Low 2020–2025

    41.2 °F

  • Average 2020–2025

    50.6 °F

  • Average High 2020–2025

    64.9 °F
Get WillyWeather+ to remove ads