| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F |
| Average First Frost Date: | Sep. 21 - Sep. 30 |
| Average Last Frost Date: | May 21 - May 31 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 25l - Front Range Fans |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 80228 - Denver, CO | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 15 | 18 | 24 | 31 | 40 | 49 | 55 | 53 | 44 | 33 | 23 | 16 | 33 |
| Avg Max Temp (°F) | 44 | 47 | 53 | 59 | 69 | 80 | 86 | 84 | 75 | 65 | 51 | 45 | 63 |
| Avg Precip (In.) | .59 | .57 | 1.48 | 2.31 | 2.7 | 2.06 | 1.83 | 1.89 | 1.4 | 1.07 | 1.11 | .69 | 17.7 |