Delmont, New Jersey has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.5 °C (low) to 17.6 °C (high). Annual precipitation averages 1182.6 Millimeters. Delmont is located in USDA Plant Hardiness Zone 7b. 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 | -3 °C | 5.6 °C | 84.84 mm |
| February | -2.6 °C | 6.4 °C | 77.22 mm |
| March | 1.2 °C | 10.2 °C | 112.78 mm |
| April | 6.7 °C | 16.6 °C | 90.42 mm |
| May | 11.9 °C | 21.6 °C | 89.41 mm |
| June | 17.3 °C | 26.8 °C | 97.28 mm |
| July | 20.4 °C | 29.3 °C | 115.57 mm |
| August | 19.4 °C | 28.4 °C | 119.38 mm |
| September | 16.2 °C | 25.2 °C | 101.09 mm |
| October | 10.1 °C | 19.4 °C | 106.17 mm |
| November | 4.2 °C | 13.3 °C | 83.57 mm |
| December | -0.2 °C | 8.2 °C | 104.9 mm |
| Annual | 8.5 °C | 17.6 °C | 1182.63 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 7b : -15°C to -12.2°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 |