Epsom, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.8 °F (low) to 57.2 °F (high). Annual precipitation averages 45.8 Inches. Epsom is located in USDA Plant Hardiness Zone 5b. 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 | 12.9 °F | 31.2 °F | 3.02 in. |
| February | 14.0 °F | 34.5 °F | 3.14 in. |
| March | 22.1 °F | 42.3 °F | 3.66 in. |
| April | 32.8 °F | 56.1 °F | 3.75 in. |
| May | 43.8 °F | 67.6 °F | 3.8 in. |
| June | 53.3 °F | 76.5 °F | 4.29 in. |
| July | 58.5 °F | 81.8 °F | 4.0 in. |
| August | 56.8 °F | 79.9 °F | 3.76 in. |
| September | 48.8 °F | 72.7 °F | 3.98 in. |
| October | 38.1 °F | 59.5 °F | 4.82 in. |
| November | 28.6 °F | 47.3 °F | 3.47 in. |
| December | 19.3 °F | 36.6 °F | 4.09 in. |
| Annual | 35.8 °F | 57.2 °F | 45.78 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |