Aspen, Colorado has a Subarctic With Cool Summers And Year Around Rainfall climate (Köppen classification: Dfc). Average annual temperatures range from -3.3 °C (low) to 13.2 °C (high). Annual precipitation averages 539.2 Millimeters. Aspen is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -14.2 °C | 0.7 °C | 40.89 mm |
| February | -12.3 °C | 2.6 °C | 42.67 mm |
| March | -7.8 °C | 7.3 °C | 46.48 mm |
| April | -3.8 °C | 11.6 °C | 68.83 mm |
| May | 0.4 °C | 17.1 °C | 54.1 mm |
| June | 4.3 °C | 23.6 °C | 27.94 mm |
| July | 7.9 °C | 26.8 °C | 39.12 mm |
| August | 7.1 °C | 25.3 °C | 42.16 mm |
| September | 3.2 °C | 21.4 °C | 48.51 mm |
| October | -2.4 °C | 14.7 °C | 42.93 mm |
| November | -8 °C | 7.1 °C | 46.74 mm |
| December | -13.5 °C | 0.7 °C | 38.86 mm |
| Annual | -3.3 °C | 13.2 °C | 539.23 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Exceptional Drought |
| Köppen Climate Classification | Dfc - Subarctic With Cool Summers And Year Around Rainfall |