| 2023 Hardiness Zone: | Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F |
| 2012 Hardiness Zone: | Zone 3b: -35°F to -30°F Zone 4a: -30°F to -25°F |
| 1990 Hardiness Zone: | Zone 3b: -35F to -30F |
| Average First Frost Date: | Sep.11 - Sep. 20 |
| Average Last Frost Date: | Jun. 1 - Jun. 10 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 82a - Aroostook Lowlands |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 04730 - Houlton, ME | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 1 | 4 | 16 | 29 | 40 | 49 | 55 | 53 | 44 | 34 | 25 | 10 | 30 |
| Avg Max Temp (°F) | 22 | 26 | 37 | 49 | 64 | 74 | 78 | 76 | 66 | 54 | 40 | 28 | 51 |
| Avg Precip (In.) | 3.26 | 2.14 | 2.66 | 2.84 | 3.28 | 3.64 | 3.54 | 3.73 | 3.48 | 3.28 | 3.59 | 3.26 | 38.71 |