Click on a day for an hourly weather forecast
The temperatures in Denver in September are comfortable with low of 13°C and and high up to 25°C.
The wather in Denver in September can vary between cold and nice weather days. Expect a few rainy days but usually not more than 3.
Our weather forecast can give you a great sense of what weather to expect in Denver in September 2026.
If you’re planning to visit Denver in the near future, we highly recommend that you review the 14 day weather forecast for Denver before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 4° / -6° | 4 | 18 | 9 | 24 mm | Awful | Denver in January |
| February | 4° / -6° | 4 | 12 | 12 | 46 mm | Awful | Denver in February |
| March | 10° / -1° | 4 | 19 | 8 | 70 mm | Bad | Denver in March |
| April | 14° / 2° | 4 | 20 | 6 | 65 mm | Ok | Denver in April |
| May | 19° / 7° | 8 | 21 | 2 | 99 mm | Bad | Denver in May |
| June | 28° / 14° | 4 | 26 | 0 | 50 mm | Perfect | Denver in June |
| July | 30° / 17° | 4 | 27 | 0 | 65 mm | Good | Denver in July |
| August | 28° / 16° | 2 | 29 | 0 | 41 mm | Perfect | Denver in August |
| September | 25° / 13° | 2 | 27 | 0 | 36 mm | Perfect | Denver in September |
| October | 16° / 5° | 2 | 26 | 3 | 33 mm | Ok | Denver in October |
| November | 11° / 0° | 2 | 23 | 5 | 24 mm | Bad | Denver in November |
| December | 4° / -6° | 4 | 17 | 9 | 23 mm | Awful | Denver in December |