| 2023 Hardiness Zone: | Zone 7b: 5°F to 10°F Zone 7a: 0°F to 5°F |
| 2012 Hardiness Zone: | Zone 6b: -5°F to 0°F |
| 1990 Hardiness Zone: | Zone 6b: -5F to 0F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 84b - Pine Barrens |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 08094 - Williamstown, NJ | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 23 | 25 | 32 | 41 | 51 | 60 | 66 | 64 | 57 | 45 | 36 | 28 | 44 |
| Avg Max Temp (°F) | 41 | 44 | 53 | 63 | 74 | 82 | 87 | 85 | 78 | 67 | 56 | 46 | 65 |
| Avg Precip (In.) | 3.83 | 2.89 | 4.14 | 3.81 | 4.11 | 3.68 | 4.26 | 4.4 | 3.89 | 3.37 | 3.49 | 3.65 | 45.51 |