| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°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. 1 - Oct. 10 |
| Average Last Frost Date: | May 21 - May 31 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 82h - Penobscot Lowlands |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 04444 - Hampden, ME | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 8 | 11 | 22 | 33 | 43 | 53 | 58 | 57 | 48 | 37 | 29 | 15 | 34 |
| Avg Max Temp (°F) | 28 | 31 | 40 | 52 | 65 | 74 | 79 | 78 | 69 | 57 | 45 | 33 | 54 |
| Avg Precip (In.) | 3.42 | 2.6 | 3.51 | 3.38 | 3.45 | 3.46 | 3.24 | 3.05 | 3.48 | 3.49 | 3.79 | 3.44 | 40.31 |