Raritan, New Jersey has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.8 °F (low) to 63.3 °F (high). Annual precipitation averages 48.3 Inches. Raritan 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 | 21.8 °F | 39.3 °F | 3.57 in. |
| February | 23.1 °F | 42.0 °F | 2.75 in. |
| March | 30.2 °F | 50.2 °F | 4.15 in. |
| April | 40.4 °F | 62.4 °F | 3.84 in. |
| May | 50.2 °F | 72.3 °F | 4.07 in. |
| June | 59.2 °F | 81.1 °F | 4.52 in. |
| July | 64.5 °F | 86.1 °F | 4.87 in. |
| August | 63.0 °F | 84.1 °F | 4.6 in. |
| September | 55.7 °F | 77.5 °F | 4.16 in. |
| October | 44.3 °F | 65.4 °F | 4.26 in. |
| November | 33.9 °F | 54.7 °F | 3.3 in. |
| December | 27.1 °F | 44.4 °F | 4.17 in. |
| Annual | 42.8 °F | 63.3 °F | 48.26 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 6a : -10°F to -5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |