Central Islip, New York has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7.3 °C (low) to 16.4 °C (high). Annual precipitation averages 1292.1 Millimeters. Central Islip is located in USDA Plant Hardiness Zone 7b. 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 | -4.2 °C | 4.2 °C | 101.09 mm |
| February | -3.6 °C | 5.2 °C | 90.93 mm |
| March | -0.1 °C | 9 °C | 129.29 mm |
| April | 5 °C | 15.2 °C | 111.76 mm |
| May | 10.4 °C | 20.7 °C | 99.31 mm |
| June | 15.9 °C | 25.5 °C | 111.25 mm |
| July | 19.3 °C | 28.5 °C | 86.61 mm |
| August | 18.7 °C | 27.6 °C | 106.17 mm |
| September | 14.9 °C | 23.9 °C | 102.11 mm |
| October | 8.8 °C | 17.7 °C | 127.25 mm |
| November | 3.2 °C | 12.1 °C | 96.52 mm |
| December | -0.9 °C | 7.2 °C | 129.79 mm |
| Annual | 7.3 °C | 16.4 °C | 1292.08 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 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |