Port Republic, New Jersey has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 45.4 °F (low) to 63.8 °F (high). Annual precipitation averages 47.7 Inches. Port Republic is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 24.6 °F | 42.2 °F | 3.69 in. |
| February | 25.7 °F | 44.1 °F | 3.02 in. |
| March | 32.6 °F | 50.5 °F | 4.71 in. |
| April | 42.4 °F | 61.6 °F | 3.55 in. |
| May | 52.1 °F | 70.8 °F | 3.51 in. |
| June | 61.7 °F | 80.1 °F | 3.84 in. |
| July | 67.3 °F | 84.8 °F | 4.71 in. |
| August | 65.6 °F | 83.3 °F | 4.76 in. |
| September | 59.2 °F | 77.6 °F | 3.67 in. |
| October | 47.2 °F | 66.7 °F | 4.23 in. |
| November | 36.8 °F | 56.3 °F | 3.44 in. |
| December | 29.8 °F | 47.0 °F | 4.52 in. |
| Annual | 45.4 °F | 63.8 °F | 47.65 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |