| 2023 Hardiness Zone: | Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F |
| Average First Frost Date: | Oct. 1 - Oct. 10 |
| 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 04989 - Vassalboro, ME | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 7 | 9 | 20 | 32 | 42 | 52 | 57 | 56 | 47 | 36 | 27 | 14 | 33 |
| Avg Max Temp (°F) | 28 | 32 | 41 | 53 | 67 | 75 | 81 | 79 | 70 | 58 | 46 | 34 | 55 |
| Avg Precip (In.) | 3.37 | 2.51 | 3.68 | 3.59 | 3.81 | 3.73 | 3.55 | 3.4 | 3.71 | 4 | 3.76 | 3.35 | 42.45 |