Mount Ephraim, New Jersey has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.6 °C (low) to 18.4 °C (high). Annual precipitation averages 1198.1 Millimeters. Mount Ephraim 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 | -3.1 °C | 5.4 °C | 90.17 mm |
| February | -2.3 °C | 6.9 °C | 70.87 mm |
| March | 1.4 °C | 11.3 °C | 113.28 mm |
| April | 7.1 °C | 18.1 °C | 89.15 mm |
| May | 12.4 °C | 23.3 °C | 98.04 mm |
| June | 17.6 °C | 28.4 °C | 108.2 mm |
| July | 20.7 °C | 30.9 °C | 119.13 mm |
| August | 19.8 °C | 29.8 °C | 123.7 mm |
| September | 16.1 °C | 26.1 °C | 103.12 mm |
| October | 9.6 °C | 19.4 °C | 97.28 mm |
| November | 3.9 °C | 13.4 °C | 78.49 mm |
| December | -0.1 °C | 8.1 °C | 106.68 mm |
| Annual | 8.6 °C | 18.4 °C | 1198.11 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 | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |