Last updated: June 24, 2025
In September, the average temperature in Denver, United States hovers around 19°C (66°F), providing a pleasant climate for exploration. Temperatures can vary, dipping to a chilly 2°C (36°F) at night or soaring to a warm 33°C (92°F) during the day. Be prepared for a bit of rain, as 129 mm (5.1 in) of precipitation can be expected over the course of 10 days. With an average humidity of 74%, the air feels pleasantly refreshing, making it a perfect time to experience all that this locale has to offer!
In September in Denver, the average temperature is 19°C (66°F). The maximum can reach 33°C (92°F) and the minimum can be as low as 2°C (36°F). This diverse climate makes Denver an ideal destination for travelers looking to experience a range of temperatures and activities.
In Denver in September, the precipitation amount is 129 mm (5.1 in) over a span of 10 days.
In Denver in September humidity is 74%. With an average temperature of 19°C (66°F), this humidity feels like a warm, enveloping blanket, making it ideal for leisurely outdoor exploration but potentially heavy for those not accustomed to tropical conditions.
In Denver in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Denver.
UV Risk Categories
Weather in Denver varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Denver, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -7°C (20°F) | 39 mm (1.6 inches) | 84% | moderate |
| February Weather | -7°C (20°F) | 52 mm (2.0 inches) | 85% | moderate |
| March Weather | 2°C (36°F) | 73 mm (2.9 inches) | 84% | moderate |
| April Weather | 8°C (47°F) | 74 mm (2.9 inches) | 83% | very high |
| May Weather | 16°C (61°F) | 174 mm (6.8 inches) | 75% | very high |
| June Weather | 22°C (72°F) | 139 mm (5.5 inches) | 79% | extreme |
| July Weather | 24°C (75°F) | 103 mm (4.1 inches) | 75% | very high |
| August Weather | 22°C (71°F) | 112 mm (4.4 inches) | 69% | very high |
| September Weather | 19°C (66°F) | 129 mm (5.1 inches) | 74% | very high |
| October Weather | 10°C (51°F) | 136 mm (5.3 inches) | 79% | moderate |
| November Weather | 2°C (36°F) | 49 mm (1.9 inches) | 88% | moderate |
| December Weather | -2°C (29°F) | 35 mm (1.4 inches) | 82% | moderate |