Unionville, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 39 °F (low) to 60.3 °F (high). Annual precipitation averages 46.3 Inches. Unionville is located in USDA Plant Hardiness Zone 6b. 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 | 17.0 °F | 35.2 °F | 3.14 in. |
| February | 18.3 °F | 38.5 °F | 2.61 in. |
| March | 25.9 °F | 46.9 °F | 3.84 in. |
| April | 36.6 °F | 59.9 °F | 3.85 in. |
| May | 46.9 °F | 70.7 °F | 3.55 in. |
| June | 56.2 °F | 78.6 °F | 4.82 in. |
| July | 60.9 °F | 83.4 °F | 3.95 in. |
| August | 59.3 °F | 81.4 °F | 4.65 in. |
| September | 52.1 °F | 74.9 °F | 4.34 in. |
| October | 40.7 °F | 62.9 °F | 4.24 in. |
| November | 30.8 °F | 51.2 °F | 3.3 in. |
| December | 23.3 °F | 40.2 °F | 3.98 in. |
| Annual | 39 °F | 60.3 °F | 46.27 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |