Folsom, New Jersey has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7 °C (low) to 18.2 °C (high). Annual precipitation averages 1217.4 Millimeters. Folsom is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.4 °C | 5.7 °C | 92.96 mm |
| February | -3.7 °C | 6.9 °C | 73.91 mm |
| March | 0.1 °C | 11 °C | 115.82 mm |
| April | 5.5 °C | 17.6 °C | 88.65 mm |
| May | 10.9 °C | 22.8 °C | 89.66 mm |
| June | 16.2 °C | 27.8 °C | 106.17 mm |
| July | 19.1 °C | 30.3 °C | 123.7 mm |
| August | 18 °C | 29.3 °C | 123.44 mm |
| September | 14.3 °C | 25.8 °C | 105.41 mm |
| October | 7.5 °C | 19.3 °C | 103.38 mm |
| November | 2.1 °C | 13.6 °C | 84.07 mm |
| December | -1.7 °C | 8.3 °C | 110.24 mm |
| Annual | 7 °C | 18.2 °C | 1217.41 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |