Hemlock, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.3 °F (low) to 57.3 °F (high). Annual precipitation averages 37.1 Inches. Hemlock is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 16.4 °F | 32.5 °F | 2.22 in. |
| February | 16.7 °F | 34.4 °F | 1.81 in. |
| March | 23.7 °F | 42.7 °F | 2.66 in. |
| April | 34.4 °F | 55.7 °F | 3.08 in. |
| May | 45.9 °F | 68.2 °F | 3.22 in. |
| June | 55.2 °F | 76.2 °F | 3.92 in. |
| July | 59.8 °F | 80.3 °F | 4.16 in. |
| August | 58.4 °F | 78.9 °F | 3.62 in. |
| September | 51.6 °F | 72.7 °F | 3.47 in. |
| October | 41.6 °F | 60.3 °F | 3.67 in. |
| November | 32.1 °F | 48.2 °F | 2.75 in. |
| December | 23.4 °F | 37.7 °F | 2.48 in. |
| Annual | 38.3 °F | 57.3 °F | 37.06 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |