| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Oct. 1 - Oct. 10 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate |
| Ecoregion: | 25d - Flat to Rolling Plains |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 80203 - Denver, CO | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 18 | 21 | 27 | 34 | 44 | 53 | 59 | 57 | 48 | 37 | 26 | 19 | 37 |
| Avg Max Temp (°F) | 44 | 48 | 53 | 60 | 70 | 81 | 86 | 85 | 76 | 65 | 52 | 45 | 64 |
| Avg Precip (In.) | .54 | .53 | 1.4 | 2.15 | 2.49 | 1.89 | 1.72 | 1.73 | 1.2 | 1.03 | .94 | .66 | 16.29 |