| 2023 Hardiness Zone: | 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: | Apr. 21 - Apr. 30 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 64a - Triassic Lowlands |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 08525 - Hopewell, NJ | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 21 | 22 | 30 | 39 | 49 | 58 | 63 | 62 | 54 | 42 | 34 | 26 | 41 |
| Avg Max Temp (°F) | 38 | 41 | 51 | 62 | 72 | 81 | 86 | 84 | 77 | 66 | 54 | 43 | 63 |
| Avg Precip (In.) | 3.78 | 2.72 | 3.84 | 3.93 | 4.7 | 3.89 | 5.03 | 4.26 | 4.52 | 3.54 | 3.83 | 3.75 | 47.77 |