Sinclairville, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.6 °C (low) to 13.4 °C (high). Annual precipitation averages 1274.3 Millimeters. Sinclairville 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 | -9.2 °C | -0.6 °C | 111.76 mm |
| February | -9.1 °C | 0.7 °C | 71.12 mm |
| March | -5.4 °C | 5.4 °C | 88.9 mm |
| April | 0.7 °C | 12.8 °C | 104.14 mm |
| May | 6.8 °C | 19.5 °C | 104.39 mm |
| June | 11.8 °C | 23.9 °C | 103.63 mm |
| July | 14 °C | 26.1 °C | 126.75 mm |
| August | 13.3 °C | 25.3 °C | 99.57 mm |
| September | 9.8 °C | 21.8 °C | 114.3 mm |
| October | 4.1 °C | 14.9 °C | 123.7 mm |
| November | -0.9 °C | 8.1 °C | 106.17 mm |
| December | -5.1 °C | 2.3 °C | 119.89 mm |
| Annual | 2.6 °C | 13.4 °C | 1274.32 mm |
| 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 : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |