Lake Ronkonkoma, New York has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7.1 °C (low) to 16.3 °C (high). Annual precipitation averages 1290.3 Millimeters. Lake Ronkonkoma 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 | -4.5 °C | 4.1 °C | 100.58 mm |
| February | -3.9 °C | 5.1 °C | 90.93 mm |
| March | -0.3 °C | 8.8 °C | 128.52 mm |
| April | 4.8 °C | 14.9 °C | 111.25 mm |
| May | 10.3 °C | 20.4 °C | 100.58 mm |
| June | 15.7 °C | 25.3 °C | 112.01 mm |
| July | 19.2 °C | 28.4 °C | 86.61 mm |
| August | 18.5 °C | 27.6 °C | 105.41 mm |
| September | 14.8 °C | 24 °C | 102.36 mm |
| October | 8.6 °C | 17.8 °C | 126.49 mm |
| November | 2.9 °C | 12.1 °C | 96.52 mm |
| December | -1.2 °C | 7.1 °C | 129.03 mm |
| Annual | 7.1 °C | 16.3 °C | 1290.29 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 |