| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Oct. 21 - Oct. 31 |
| Average Last Frost Date: | May 1 - May 10 |
| 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 04679 - Southwest Harbor, ME | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 13 | 15 | 25 | 33 | 43 | 51 | 57 | 56 | 49 | 40 | 31 | 20 | 36 |
| Avg Max Temp (°F) | 30 | 33 | 41 | 53 | 65 | 73 | 78 | 77 | 68 | 57 | 46 | 36 | 55 |
| Avg Precip (In.) | 5.37 | 3.94 | 4.54 | 4.23 | 3.82 | 3.61 | 3.21 | 2.73 | 4.22 | 4.6 | 5.28 | 4.87 | 50.41 |