Rumson, New Jersey has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 8.4 °C (low) to 16.5 °C (high). Annual precipitation averages 1198.4 Millimeters. Rumson 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 | -3.3 °C | 4.6 °C | 94.49 mm |
| February | -2.6 °C | 5.6 °C | 71.63 mm |
| March | 1 °C | 9.1 °C | 105.66 mm |
| April | 6.3 °C | 14.9 °C | 99.31 mm |
| May | 11.5 °C | 20.1 °C | 92.46 mm |
| June | 16.9 °C | 25.4 °C | 110.74 mm |
| July | 20.4 °C | 28.3 °C | 104.65 mm |
| August | 19.9 °C | 27.5 °C | 123.7 mm |
| September | 16.3 °C | 24.2 °C | 97.28 mm |
| October | 9.9 °C | 18.3 °C | 108.97 mm |
| November | 4.3 °C | 12.6 °C | 79.25 mm |
| December | -0.2 °C | 7.7 °C | 110.24 mm |
| Annual | 8.4 °C | 16.5 °C | 1198.38 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| 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 7a : -17.8°C to -15°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |