| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Sep.11 - Sep. 20 |
| Average Last Frost Date: | Jun. 11 - Jun. 20 |
| Koppen-Geiger Climate Zone: | Dsa - Humid Continental Climate - Dry Warm Summer |
| Ecoregion: | 16k - Southern Forested Mountains |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 83631 - Idaho City, ID | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 15 | 18 | 24 | 30 | 37 | 42 | 47 | 47 | 39 | 30 | 22 | 14 | 30 |
| Avg Max Temp (°F) | 35 | 41 | 49 | 57 | 66 | 75 | 85 | 85 | 74 | 61 | 42 | 34 | 58 |
| Avg Precip (In.) | 3.4 | 2.8 | 2.45 | 1.9 | 1.85 | 1.3 | .65 | .51 | 1.15 | 1.44 | 3.05 | 3.46 | 23.97 |