| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5a: -20°F to -15°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 4a: -30F to -25F | |
| Average First Frost Date: | Sep.1 - Sep. 10 | |
| Average Last Frost Date: | Jun. 11 - Jun. 20 | |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate | |
| Ecoregion: | 12e - Upper Snake River Plain | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 83427 - Iona, ID | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 11 | 15 | 23 | 30 | 38 | 45 | 50 | 48 | 39 | 30 | 21 | 12 | 30 |
| Avg Max Temp (°F) | 29 | 36 | 46 | 56 | 66 | 76 | 85 | 84 | 73 | 60 | 42 | 31 | 57 |
| Avg Precip (In.) | 1.14 | .93 | 1.16 | 1.12 | 1.9 | 1.19 | .78 | .86 | .88 | 1.04 | 1.12 | 1.1 | 13.22 |