| 2023 Hardiness Zone: | Zone 7a: 0°F to 5°F |
| 2012 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°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 08530 - Lambertville, 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 | 42 |
| Avg Max Temp (°F) | 39 | 42 | 51 | 63 | 73 | 82 | 86 | 85 | 77 | 66 | 54 | 44 | 64 |
| Avg Precip (In.) | 3.98 | 2.87 | 4.11 | 3.96 | 4.6 | 4.03 | 4.98 | 4.29 | 4.52 | 3.5 | 3.81 | 3.69 | 48.34 |