Belvidere, New Jersey has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.9 °C (low) to 16.8 °C (high). Annual precipitation averages 1240.5 Millimeters. Belvidere 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.7 °C | 3.2 °C | 84.33 mm |
| February | -5.9 °C | 4.9 °C | 69.85 mm |
| March | -2.1 °C | 9.6 °C | 99.57 mm |
| April | 3.4 °C | 16.6 °C | 95 mm |
| May | 9.2 °C | 22.1 °C | 104.9 mm |
| June | 14.3 °C | 26.6 °C | 119.89 mm |
| July | 17 °C | 29.2 °C | 119.13 mm |
| August | 15.9 °C | 28.1 °C | 118.36 mm |
| September | 12.1 °C | 24.6 °C | 121.41 mm |
| October | 5.6 °C | 18.2 °C | 119.38 mm |
| November | 0.2 °C | 11.9 °C | 84.58 mm |
| December | -3.7 °C | 6.1 °C | 104.14 mm |
| Annual | 4.9 °C | 16.8 °C | 1240.54 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |