Fortescue, New Jersey has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.1 °C (low) to 17.1 °C (high). Annual precipitation averages 1113.8 Millimeters. Fortescue is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.3 °C | 5.3 °C | 81.28 mm |
| February | -1.9 °C | 5.8 °C | 73.15 mm |
| March | 1.7 °C | 9.9 °C | 102.87 mm |
| April | 7.3 °C | 15.7 °C | 85.6 mm |
| May | 12.7 °C | 20.6 °C | 94.23 mm |
| June | 17.9 °C | 26.2 °C | 99.57 mm |
| July | 21.2 °C | 28.6 °C | 108.2 mm |
| August | 20.2 °C | 27.9 °C | 107.95 mm |
| September | 16.9 °C | 24.9 °C | 94.49 mm |
| October | 10.7 °C | 18.8 °C | 94.49 mm |
| November | 4.9 °C | 13.1 °C | 75.69 mm |
| December | 0.4 °C | 8 °C | 96.27 mm |
| Annual | 9.1 °C | 17.1 °C | 1113.79 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |