| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F |
| 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: | 82e - Central Maine Embayment |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 04354 - Palermo, ME | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 8 | 10 | 21 | 32 | 42 | 52 | 57 | 56 | 47 | 37 | 28 | 15 | 34 |
| Avg Max Temp (°F) | 29 | 32 | 41 | 53 | 65 | 74 | 79 | 77 | 69 | 58 | 45 | 34 | 55 |
| Avg Precip (In.) | 3.67 | 2.76 | 3.98 | 4 | 3.98 | 3.81 | 3.51 | 3.33 | 3.77 | 4.17 | 4.22 | 3.73 | 44.91 |