Denver, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 3.2 °C (low) to 18.6 °C (high). Annual precipitation averages 401.3 Millimeters. Denver is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7 °C | 8 °C | 12.95 mm |
| February | -6.2 °C | 8.4 °C | 15.49 mm |
| March | -1.8 °C | 13.4 °C | 33.02 mm |
| April | 1.8 °C | 16.7 °C | 53.09 mm |
| May | 6.9 °C | 21.6 °C | 59.69 mm |
| June | 12.2 °C | 28.3 °C | 41.66 mm |
| July | 15.7 °C | 31.8 °C | 51.05 mm |
| August | 14.6 °C | 30.5 °C | 43.69 mm |
| September | 9.7 °C | 26.2 °C | 30.23 mm |
| October | 2.8 °C | 18.8 °C | 27.94 mm |
| November | -2.7 °C | 12.4 °C | 19.05 mm |
| December | -7.2 °C | 7.5 °C | 13.46 mm |
| Annual | 3.2 °C | 18.6 °C | 401.32 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |