| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°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: | 82f - Midcoast |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 04538 - Boothbay Harbor, ME | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 12 | 15 | 25 | 34 | 44 | 53 | 59 | 58 | 49 | 39 | 30 | 19 | 36 |
| Avg Max Temp (°F) | 31 | 34 | 42 | 53 | 65 | 74 | 79 | 78 | 69 | 59 | 47 | 36 | 56 |
| Avg Precip (In.) | 4.22 | 3.38 | 4.44 | 4.27 | 3.97 | 3.6 | 3.29 | 2.95 | 3.76 | 4.14 | 4.78 | 4.41 | 47.21 |