Halfmoon, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.9 °F (low) to 58.3 °F (high). Annual precipitation averages 42.8 Inches. Halfmoon is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 15.3 °F | 31.9 °F | 2.96 in. |
| February | 16.6 °F | 34.7 °F | 2.19 in. |
| March | 24.9 °F | 43.7 °F | 2.97 in. |
| April | 36.4 °F | 57.9 °F | 3.38 in. |
| May | 47.9 °F | 69.7 °F | 3.57 in. |
| June | 56.9 °F | 78.0 °F | 4.66 in. |
| July | 61.2 °F | 83.4 °F | 4.51 in. |
| August | 60.2 °F | 80.7 °F | 4.23 in. |
| September | 52.4 °F | 73.6 °F | 3.82 in. |
| October | 41.2 °F | 60.8 °F | 4.13 in. |
| November | 31.2 °F | 48.3 °F | 3.03 in. |
| December | 22.4 °F | 37.1 °F | 3.34 in. |
| Annual | 38.9 °F | 58.3 °F | 42.79 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 |