Shirley, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 6.6 °C (low) to 16.2 °C (high). Annual precipitation averages 1200.9 Millimeters. Shirley is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.8 °C | 4.1 °C | 96.77 mm |
| February | -4.2 °C | 5.1 °C | 88.14 mm |
| March | -0.7 °C | 8.7 °C | 124.21 mm |
| April | 4.3 °C | 14.5 °C | 106.43 mm |
| May | 9.7 °C | 20 °C | 88.9 mm |
| June | 15.1 °C | 24.9 °C | 98.81 mm |
| July | 18.6 °C | 28.1 °C | 78.99 mm |
| August | 18.1 °C | 27.4 °C | 93.98 mm |
| September | 14.3 °C | 23.9 °C | 89.92 mm |
| October | 8.2 °C | 17.8 °C | 118.36 mm |
| November | 2.7 °C | 12.2 °C | 96.27 mm |
| December | -1.6 °C | 7.1 °C | 120.14 mm |
| Annual | 6.6 °C | 16.2 °C | 1200.92 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |