Jaffrey, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.7 °F (low) to 56.3 °F (high). Annual precipitation averages 49.3 Inches. Jaffrey is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 12.6 °F | 30.9 °F | 3.63 in. |
| February | 14.0 °F | 34.0 °F | 3.31 in. |
| March | 21.6 °F | 41.7 °F | 4.09 in. |
| April | 32.9 °F | 55.1 °F | 3.92 in. |
| May | 43.5 °F | 66.6 °F | 3.95 in. |
| June | 52.9 °F | 75.2 °F | 4.51 in. |
| July | 58.3 °F | 80.2 °F | 4.33 in. |
| August | 56.6 °F | 78.7 °F | 4.04 in. |
| September | 49.1 °F | 71.3 °F | 3.98 in. |
| October | 38.1 °F | 58.5 °F | 5.26 in. |
| November | 28.8 °F | 46.9 °F | 3.89 in. |
| December | 19.4 °F | 36.3 °F | 4.38 in. |
| Annual | 35.7 °F | 56.3 °F | 49.29 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| 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 |