Hamden, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35 °F (low) to 57 °F (high). Annual precipitation averages 47.6 Inches. Hamden 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 | 12.9 °F | 31.6 °F | 3.26 in. |
| February | 14.1 °F | 34.5 °F | 2.62 in. |
| March | 21.1 °F | 42.4 °F | 3.5 in. |
| April | 32.0 °F | 56.4 °F | 3.88 in. |
| May | 42.4 °F | 68.2 °F | 4.1 in. |
| June | 51.8 °F | 76.1 °F | 4.78 in. |
| July | 56.2 °F | 80.5 °F | 4.73 in. |
| August | 55.1 °F | 79.1 °F | 4.71 in. |
| September | 48.1 °F | 72.3 °F | 4.42 in. |
| October | 37.4 °F | 60.0 °F | 4.48 in. |
| November | 28.4 °F | 47.0 °F | 3.45 in. |
| December | 20.3 °F | 36.4 °F | 3.66 in. |
| Annual | 35 °F | 57 °F | 47.59 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 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |