Richmond, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.4 °F (low) to 56.7 °F (high). Annual precipitation averages 48.6 Inches. Richmond is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 12.1 °F | 31.1 °F | 3.65 in. |
| February | 13.8 °F | 34.3 °F | 3.14 in. |
| March | 21.5 °F | 42.0 °F | 3.73 in. |
| April | 32.9 °F | 55.4 °F | 3.74 in. |
| May | 43.2 °F | 67.4 °F | 3.83 in. |
| June | 52.9 °F | 75.9 °F | 4.59 in. |
| July | 58.1 °F | 81.0 °F | 4.28 in. |
| August | 55.6 °F | 79.2 °F | 4.31 in. |
| September | 47.9 °F | 71.3 °F | 4.33 in. |
| October | 38.0 °F | 58.9 °F | 5.04 in. |
| November | 29.0 °F | 47.2 °F | 3.73 in. |
| December | 19.3 °F | 36.5 °F | 4.18 in. |
| Annual | 35.4 °F | 56.7 °F | 48.55 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |