Washington Mills, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.7 °F (low) to 57.2 °F (high). Annual precipitation averages 47.9 Inches. Washington Mills is located in USDA Plant Hardiness Zone 5b. 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 | 13.9 °F | 30.5 °F | 3.11 in. |
| February | 15.0 °F | 32.8 °F | 2.79 in. |
| March | 23.0 °F | 41.0 °F | 3.52 in. |
| April | 34.7 °F | 56.1 °F | 4.08 in. |
| May | 46.0 °F | 69.2 °F | 3.97 in. |
| June | 55.5 °F | 77.8 °F | 4.82 in. |
| July | 60.3 °F | 82.3 °F | 4.8 in. |
| August | 58.9 °F | 80.5 °F | 4.38 in. |
| September | 51.6 °F | 73.3 °F | 4.11 in. |
| October | 41.0 °F | 60.0 °F | 4.6 in. |
| November | 31.2 °F | 47.0 °F | 4.01 in. |
| December | 21.6 °F | 35.8 °F | 3.67 in. |
| Annual | 37.7 °F | 57.2 °F | 47.86 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 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 |