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.
Thornton Temperature Statistics
September Temperature
Broomfield / Jeffco (6.8 miles)
Lowest 6 September, 2025
48.2 °FAverage September
65.9 °FHighest 10 September, 2025
91.4 °F
Climate (2020–Present)
Broomfield / Jeffco (6.8 miles)
Average Low 2020–2025
41.2 °FAverage 2020–2025
50.6 °FAverage High 2020–2025
64.9 °F