Wellsville, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34.3 °F (low) to 56.6 °F (high). Annual precipitation averages 39.8 Inches. Wellsville is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.1 °F | 31.5 °F | 2.73 in. |
| February | 14.3 °F | 33.9 °F | 1.85 in. |
| March | 20.5 °F | 42.4 °F | 2.53 in. |
| April | 30.9 °F | 55.6 °F | 3.65 in. |
| May | 41.6 °F | 68.2 °F | 3.64 in. |
| June | 50.6 °F | 75.9 °F | 4.12 in. |
| July | 54.8 °F | 79.8 °F | 4.14 in. |
| August | 53.6 °F | 78.1 °F | 3.87 in. |
| September | 46.8 °F | 71.7 °F | 3.7 in. |
| October | 36.6 °F | 59.0 °F | 3.95 in. |
| November | 27.9 °F | 46.7 °F | 2.72 in. |
| December | 20.3 °F | 36.1 °F | 2.93 in. |
| Annual | 34.3 °F | 56.6 °F | 39.83 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| 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 |