Richwood, New Jersey has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.8 °C (low) to 18.1 °C (high). Annual precipitation averages 1209.3 Millimeters. Richwood is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.9 °C | 5.2 °C | 96.77 mm |
| February | -3.1 °C | 6.5 °C | 73.15 mm |
| March | 0.5 °C | 10.9 °C | 115.06 mm |
| April | 6.3 °C | 17.7 °C | 91.44 mm |
| May | 11.6 °C | 23 °C | 95.76 mm |
| June | 16.9 °C | 28.1 °C | 110.24 mm |
| July | 19.9 °C | 30.4 °C | 119.38 mm |
| August | 19 °C | 29.3 °C | 116.33 mm |
| September | 15.3 °C | 25.8 °C | 104.14 mm |
| October | 8.5 °C | 19.2 °C | 101.35 mm |
| November | 2.9 °C | 13.2 °C | 77.47 mm |
| December | -0.9 °C | 7.9 °C | 108.2 mm |
| Annual | 7.8 °C | 18.1 °C | 1209.29 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| 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 | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |