Jamesburg, New Jersey has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.8 °F (low) to 64 °F (high). Annual precipitation averages 48.5 Inches. Jamesburg is located in USDA Plant Hardiness Zone 7a. 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 | 23.2 °F | 40.3 °F | 3.6 in. |
| February | 24.6 °F | 42.9 °F | 2.76 in. |
| March | 31.5 °F | 50.6 °F | 4.32 in. |
| April | 41.4 °F | 62.8 °F | 3.82 in. |
| May | 51.0 °F | 72.7 °F | 3.98 in. |
| June | 60.0 °F | 81.7 °F | 4.57 in. |
| July | 65.6 °F | 86.6 °F | 4.87 in. |
| August | 63.9 °F | 84.5 °F | 4.55 in. |
| September | 56.6 °F | 78.3 °F | 4.19 in. |
| October | 45.0 °F | 66.1 °F | 4.07 in. |
| November | 35.0 °F | 55.7 °F | 3.39 in. |
| December | 28.1 °F | 45.4 °F | 4.37 in. |
| Annual | 43.8 °F | 64 °F | 48.49 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |