Mystic Island, New Jersey has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.1 °C (low) to 17.6 °C (high). Annual precipitation averages 1198.1 Millimeters. Mystic Island 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. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.5 °C | 5.8 °C | 93.73 mm |
| February | -2.9 °C | 6.7 °C | 75.69 mm |
| March | 0.7 °C | 10.2 °C | 119.63 mm |
| April | 6 °C | 16.1 °C | 88.39 mm |
| May | 11.3 °C | 21.3 °C | 87.63 mm |
| June | 16.9 °C | 26.6 °C | 95.25 mm |
| July | 20.1 °C | 29.3 °C | 120.65 mm |
| August | 19.4 °C | 28.4 °C | 125.73 mm |
| September | 16.1 °C | 25.2 °C | 88.65 mm |
| October | 9.6 °C | 19.4 °C | 105.41 mm |
| November | 3.9 °C | 13.5 °C | 84.33 mm |
| December | -0.3 °C | 8.4 °C | 113.03 mm |
| Annual | 8.1 °C | 17.6 °C | 1198.12 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |