Newfoundland, New Jersey has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 5.1 °C (low) to 16.1 °C (high). Annual precipitation averages 1312.1 Millimeters. Newfoundland is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.7 °C | 2.6 °C | 102.36 mm |
| February | -6.4 °C | 3.9 °C | 75.95 mm |
| March | -2.2 °C | 8.3 °C | 119.63 mm |
| April | 3.9 °C | 15.4 °C | 101.85 mm |
| May | 8.9 °C | 21.3 °C | 98.04 mm |
| June | 14.3 °C | 25.9 °C | 128.52 mm |
| July | 16.9 °C | 29.4 °C | 106.17 mm |
| August | 16.7 °C | 28.2 °C | 120.9 mm |
| September | 12.1 °C | 24.4 °C | 122.17 mm |
| October | 5.9 °C | 17.8 °C | 114.55 mm |
| November | 0.8 °C | 11.3 °C | 101.09 mm |
| December | -3.3 °C | 5.2 °C | 120.9 mm |
| Annual | 5.1 °C | 16.1 °C | 1312.13 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |