National Park, New Jersey has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.1 °C (low) to 18.4 °C (high). Annual precipitation averages 1183.1 Millimeters. National Park is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.6 °C | 5.4 °C | 89.15 mm |
| February | -1.8 °C | 6.8 °C | 70.61 mm |
| March | 1.9 °C | 11.2 °C | 111 mm |
| April | 7.6 °C | 18 °C | 88.9 mm |
| May | 12.8 °C | 23.3 °C | 95.25 mm |
| June | 18.1 °C | 28.4 °C | 106.93 mm |
| July | 21.2 °C | 30.9 °C | 116.59 mm |
| August | 20.4 °C | 29.8 °C | 120.4 mm |
| September | 16.7 °C | 26.1 °C | 104.14 mm |
| October | 10.2 °C | 19.5 °C | 96.77 mm |
| November | 4.4 °C | 13.4 °C | 77.22 mm |
| December | 0.3 °C | 8.1 °C | 106.17 mm |
| Annual | 9.1 °C | 18.4 °C | 1183.13 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |