| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | 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 11 - May 20 |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate |
| Ecoregion: | 25c - Moderate Relief Plains |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 80126 - Littleton, CO | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 15 | 19 | 26 | 33 | 42 | 52 | 57 | 56 | 46 | 34 | 23 | 16 | 35 |
| Avg Max Temp (°F) | 44 | 48 | 55 | 61 | 70 | 81 | 87 | 85 | 77 | 66 | 53 | 45 | 64 |
| Avg Precip (In.) | .6 | .58 | 1.54 | 2.36 | 2.75 | 1.92 | 1.83 | 1.78 | 1.41 | 1.09 | 1.15 | .71 | 17.71 |