Belleplain, New Jersey has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.5 °C (low) to 18.2 °C (high). Annual precipitation averages 1207.5 Millimeters. Belleplain is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.1 °C | 6.1 °C | 85.34 mm |
| February | -3.6 °C | 7.3 °C | 79.25 mm |
| March | 0.2 °C | 11.1 °C | 116.33 mm |
| April | 5.8 °C | 17.3 °C | 92.46 mm |
| May | 11.1 °C | 22.3 °C | 88.65 mm |
| June | 16.3 °C | 27.3 °C | 96.77 mm |
| July | 19.4 °C | 29.9 °C | 118.87 mm |
| August | 18.5 °C | 28.9 °C | 121.92 mm |
| September | 15.1 °C | 25.8 °C | 103.38 mm |
| October | 8.9 °C | 19.7 °C | 109.98 mm |
| November | 3.1 °C | 13.9 °C | 86.36 mm |
| December | -1.3 °C | 8.8 °C | 108.2 mm |
| Annual | 7.5 °C | 18.2 °C | 1207.51 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |