Baseline Sub Weather Forecast
- 64
- 91
Chance Rain Showers
- 62
- 89
Slight Chance Thunderstorms
- 60
- 87
Mostly Sunny
- 58
- 85
Mostly Sunny
- 62
- 91
Mostly Sunny
- 60
- 91
Mostly Sunny
- 56
- 88
Chance Thunderstorms
Today 6 Sep Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County
Partly cloudy. Slight chance of Thunderstorms late in the afternoon. Highs 87 to 93. Chance of precipitation 20 percent.
Tonight 6 Sep Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County
Mostly cloudy with a chance of Showers and slight chance of Thunderstorms early in the Evening, then mostly cloudy with a chance of Showers during the late evening hours. Partly cloudy after midnight. Lows in the lower to mid 60s. Chance of rain 30 percent.
Baseline Sub Temperature Statistics
September Temperature
Boulder Municipal Airport (2.5 miles)
Lowest 3 September, 2026
59 °FAverage September
75.8 °FHighest 4 September, 2026
95 °F
Climate (2021–2026)
Boulder Municipal Airport (2.5 miles)
Average Low 2021–2026
41.3 °FAverage 2021–2026
53.7 °FAverage High 2021–2026
66.4 °F