Hampden, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34.3 °F (low) to 54.6 °F (high). Annual precipitation averages 47.6 Inches. Hampden is located in USDA Plant Hardiness Zone 5a. 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 | 8.2 °F | 28.1 °F | 3.65 in. |
| February | 10.1 °F | 31.2 °F | 3.33 in. |
| March | 20.9 °F | 39.5 °F | 4.25 in. |
| April | 32.0 °F | 52.1 °F | 4.31 in. |
| May | 42.5 °F | 64.5 °F | 3.63 in. |
| June | 51.7 °F | 73.7 °F | 4.0 in. |
| July | 58.1 °F | 79.4 °F | 3.26 in. |
| August | 56.3 °F | 78.5 °F | 3.36 in. |
| September | 48.6 °F | 70.5 °F | 3.89 in. |
| October | 37.8 °F | 57.6 °F | 4.89 in. |
| November | 28.6 °F | 45.6 °F | 4.15 in. |
| December | 17.1 °F | 34.4 °F | 4.88 in. |
| Annual | 34.3 °F | 54.6 °F | 47.6 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |