Exeter, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.5 °F (low) to 58.4 °F (high). Annual precipitation averages 48.4 Inches. Exeter is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 15.3 °F | 34.0 °F | 3.5 in. |
| February | 16.9 °F | 36.6 °F | 3.4 in. |
| March | 24.5 °F | 44.0 °F | 4.4 in. |
| April | 34.6 °F | 56.4 °F | 4.33 in. |
| May | 44.6 °F | 66.8 °F | 3.9 in. |
| June | 54.2 °F | 76.1 °F | 4.25 in. |
| July | 60.0 °F | 81.9 °F | 3.7 in. |
| August | 58.4 °F | 80.8 °F | 3.52 in. |
| September | 50.6 °F | 73.4 °F | 3.94 in. |
| October | 39.0 °F | 61.2 °F | 4.97 in. |
| November | 30.3 °F | 50.0 °F | 3.9 in. |
| December | 21.8 °F | 39.1 °F | 4.56 in. |
| Annual | 37.5 °F | 58.4 °F | 48.37 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |