| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 82g - Downeast Coast |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 04642 - Harborside, ME | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 11 | 13 | 23 | 33 | 42 | 52 | 57 | 56 | 49 | 39 | 31 | 18 | 35 |
| Avg Max Temp (°F) | 31 | 34 | 42 | 53 | 65 | 74 | 79 | 78 | 70 | 59 | 48 | 36 | 56 |
| Avg Precip (In.) | 4.17 | 3.16 | 4.36 | 4.34 | 4.06 | 3.75 | 3.26 | 2.96 | 4.01 | 4.24 | 4.74 | 4.3 | 47.36 |