Alexandria, New Hampshire has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32.7 °F (low) to 51.7 °F (high). Annual precipitation averages 57.6 Inches. Alexandria is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 7.3 °F | 24.4 °F | 3.61 in. |
| February | 9.0 °F | 28.1 °F | 3.35 in. |
| March | 17.4 °F | 37.0 °F | 4.4 in. |
| April | 30.2 °F | 50.6 °F | 4.63 in. |
| May | 41.9 °F | 63.7 °F | 4.98 in. |
| June | 51.1 °F | 72.0 °F | 5.82 in. |
| July | 55.6 °F | 76.6 °F | 4.93 in. |
| August | 54.6 °F | 75.1 °F | 4.48 in. |
| September | 47.4 °F | 67.7 °F | 4.56 in. |
| October | 36.3 °F | 54.6 °F | 6.47 in. |
| November | 26.1 °F | 41.0 °F | 4.88 in. |
| December | 15.1 °F | 30.0 °F | 5.44 in. |
| Annual | 32.7 °F | 51.7 °F | 57.55 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |