| 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. 21 - Oct. 31 |
| Average Last Frost Date: | Apr. 21 - Apr. 30 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 84d - Inner Coastal Plain |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 08501 - Allentown, NJ | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 22 | 23 | 31 | 39 | 49 | 59 | 64 | 62 | 55 | 43 | 35 | 27 | 42 |
| Avg Max Temp (°F) | 39 | 42 | 51 | 62 | 72 | 81 | 86 | 84 | 77 | 66 | 55 | 44 | 63 |
| Avg Precip (In.) | 3.83 | 2.86 | 4.03 | 3.89 | 4.44 | 3.82 | 4.99 | 4.64 | 4.42 | 3.46 | 3.73 | 3.74 | 47.83 |