Long Hill, Connecticut has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.5 °C (low) to 15.6 °C (high). Annual precipitation averages 1298.2 Millimeters. Long Hill 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 | -6.4 °C | 2.5 °C | 98.81 mm |
| February | -5.8 °C | 3.8 °C | 81.53 mm |
| March | -1.9 °C | 8.2 °C | 113.03 mm |
| April | 3.6 °C | 14.8 °C | 106.68 mm |
| May | 9 °C | 20.8 °C | 102.62 mm |
| June | 14.3 °C | 25.4 °C | 122.43 mm |
| July | 17.7 °C | 28.3 °C | 93.73 mm |
| August | 17.1 °C | 27.2 °C | 113.54 mm |
| September | 13.1 °C | 23.4 °C | 121.67 mm |
| October | 6.9 °C | 17.1 °C | 123.95 mm |
| November | 1.3 °C | 10.9 °C | 107.44 mm |
| December | -3.1 °C | 5.3 °C | 112.78 mm |
| Annual | 5.5 °C | 15.6 °C | 1298.21 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |