| 2023 Hardiness Zone: | Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F |
| Average First Frost Date: | Sep. 21 - Sep. 30 |
| Average Last Frost Date: | May 21 - May 31 |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate |
| Ecoregion: | 26i - Pine-Oak Woodlands |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 80104 - Castle Rock, CO | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 13 | 16 | 22 | 29 | 38 | 47 | 53 | 51 | 42 | 31 | 20 | 14 | 31 |
| Avg Max Temp (°F) | 43 | 46 | 52 | 58 | 67 | 78 | 84 | 82 | 74 | 65 | 51 | 45 | 62 |
| Avg Precip (In.) | .56 | .54 | 1.54 | 1.95 | 2.59 | 1.94 | 2.38 | 2.22 | 1.3 | 1.09 | 1.04 | .72 | 17.87 |