Denver weather in September
Temperature, rain and sunshine in September: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in September
Excellent
Best time to visit: May – June, August – October
What is the weather like in Denver in September?
In September, Denver is warm: daytime highs average 25 °C, and nights cool down to about 10 °C. The sun shines for around 8 hours a day. Rain falls on about 6 days, adding up to 38 mm. All in all, September is an excellent month for a holiday in Denver.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 80 | 92 | 85 |
| Day | 29° | 25° | 18° |
| Night | 14° | 10° | 3° |
| Sun | 9 h | 8 h | 7 h |
| Rain days | 8 | 6 | 6 |
More details for September
- Daylight
- 12 h 31 min06:40 – 19:11
- UV index
- 7 · highclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 14 km/haverage daily peakAll months
- Cloud cover
- 35 %on averageAll months
- Hot days
- 4 days30 °C or moreAll months
- Snow days
- 0 days1 cm or more of fresh snowAll months
- Time zone
- UTC−6America/Denver
How the score comes together
- Temperatureweight 50 %100 %
- Sunshineweight 20 %80 %
- Few rainy daysweight 30 %86 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in September
- Sunscreen
- Sunglasses & sun hat
- Light, breathable clothes
- A jumper for the evenings
Denver in September: quick answers
Is Denver hot in September?
Warm rather than hot: in September, daytime highs in Denver average 25 °C and nights cool to about 10 °C. On about 4 days the thermometer climbs to 30 °C or more.
Does it rain much in Denver in September?
Rain falls on about 6 days, adding up to 38 mm.
Denver month by month
The whole year in DenverAll destinations: USAWhere to go in September
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences