Clay, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.4 °C (low) to 13.9 °C (high). Annual precipitation averages 1152.4 Millimeters. Clay is located in USDA Plant Hardiness Zone 5b. 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 | -9.4 °C | -0.6 °C | 93.22 mm |
| February | -9.1 °C | 0.7 °C | 78.49 mm |
| March | -4.8 °C | 4.9 °C | 86.87 mm |
| April | 1.6 °C | 13.1 °C | 89.92 mm |
| May | 7.9 °C | 20.2 °C | 93.98 mm |
| June | 12.9 °C | 24.7 °C | 102.36 mm |
| July | 15.6 °C | 27.3 °C | 99.57 mm |
| August | 14.8 °C | 26.6 °C | 96.27 mm |
| September | 10.9 °C | 22.7 °C | 96.01 mm |
| October | 5.3 °C | 15.4 °C | 117.6 mm |
| November | 0.2 °C | 8.7 °C | 98.04 mm |
| December | -5.2 °C | 2.6 °C | 100.08 mm |
| Annual | 3.4 °C | 13.9 °C | 1152.41 mm |
| 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 5b : -26.1°C to -23.3°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 |