| 2023 Hardiness Zone: | Zone 7b: 5°F to 10°F Zone 7a: 0°F to 5°F |
| 2012 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F |
| 1990 Hardiness Zone: | Zone 6a: -10F to -5F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate |
| Ecoregion: | 12a - Treasure Valley |
| Heat Zone Days: | 46 - 60 days Over 86°F |
Annual Climate Data for ZIP Code 83644 - Middleton, ID | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 21 | 26 | 32 | 37 | 44 | 51 | 56 | 54 | 45 | 36 | 28 | 21 | 38 |
| Avg Max Temp (°F) | 37 | 45 | 56 | 65 | 73 | 82 | 90 | 90 | 79 | 66 | 49 | 38 | 64 |
| Avg Precip (In.) | 1.42 | 1.12 | 1.27 | 1.06 | 1.07 | .7 | .3 | .32 | .6 | .71 | 1.28 | 1.39 | 11.23 |