| 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 5a: -20°F to -15°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F |
| Average First Frost Date: | Aug. 21 - Aug. 31 |
| Average Last Frost Date: | Jun. 1 - Jun. 10 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 21c - Crystalline Mid-Elevation Forests and Shrublands |
| Heat Zone Days: | 8 - 14 days Over 86°F |
Annual Climate Data for ZIP Code 80455 - Jamestown, CO | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 15 | 17 | 21 | 26 | 34 | 41 | 50 | 46 | 38 | 29 | 23 | 16 | 30 |
| Avg Max Temp (°F) | 39 | 42 | 47 | 53 | 63 | 75 | 81 | 78 | 70 | 61 | 45 | 42 | 58 |
| Avg Precip (In.) | .84 | .87 | 1.86 | 2.7 | 3.06 | 1.99 | 1.96 | 2.05 | 1.56 | 1.28 | 1.28 | .88 | 20.34 |