| 2023 Hardiness Zone: | Zone 7b: 5°F to 10°F | |
| 2012 Hardiness Zone: | Zone 7a: 0°F to 5°F | |
| 1990 Hardiness Zone: | Zone 7a: 0F to 5F | |
| Average First Frost Date: | Nov. 1 - Nov. 10 | |
| Average Last Frost Date: | Apr. 1 - Apr. 10 | |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year | |
| Ecoregion: | 84a - Cape Cod and Islands | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 02646 - Harwich Port, MA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 23 | 24 | 30 | 39 | 48 | 56 | 62 | 62 | 56 | 46 | 38 | 29 | 43 |
| Avg Max Temp (°F) | 38 | 38 | 44 | 51 | 61 | 70 | 76 | 75 | 70 | 60 | 51 | 43 | 56 |
| Avg Precip (In.) | 4.19 | 3.77 | 4.12 | 3.89 | 3.59 | 3.36 | 3.22 | 3.38 | 3.78 | 4.07 | 3.96 | 4.46 | 45.8 |