Bartlett, New Hampshire has a Subarctic With Cool Summers And Year Around Rainfall climate (Köppen classification: Dfc). Average annual temperatures range from 33 °F (low) to 55.7 °F (high). Annual precipitation averages 52.7 Inches. Bartlett is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 8.5 °F | 29.6 °F | 3.71 in. |
| February | 9.7 °F | 32.4 °F | 3.47 in. |
| March | 19.2 °F | 40.9 °F | 3.95 in. |
| April | 30.7 °F | 54.3 °F | 4.42 in. |
| May | 42.0 °F | 67.1 °F | 4.25 in. |
| June | 51.1 °F | 75.3 °F | 4.8 in. |
| July | 56.1 °F | 80.3 °F | 4.81 in. |
| August | 54.3 °F | 79.0 °F | 4.16 in. |
| September | 46.2 °F | 71.5 °F | 4.11 in. |
| October | 35.6 °F | 58.0 °F | 5.55 in. |
| November | 26.4 °F | 45.3 °F | 4.47 in. |
| December | 16.4 °F | 34.8 °F | 4.96 in. |
| Annual | 33 °F | 55.7 °F | 52.66 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfc - Subarctic With Cool Summers And Year Around Rainfall |