Union City, New Jersey has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 8.9 °C (low) to 17 °C (high). Annual precipitation averages 1204.2 Millimeters. Union City is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.9 °C | 4 °C | 90.17 mm |
| February | -2.2 °C | 5.4 °C | 71.37 mm |
| March | 1.4 °C | 9.5 °C | 108.2 mm |
| April | 7.1 °C | 16.1 °C | 103.38 mm |
| May | 12.3 °C | 21.6 °C | 98.3 mm |
| June | 17.7 °C | 26.8 °C | 110.74 mm |
| July | 21.2 °C | 29.6 °C | 111.25 mm |
| August | 20.3 °C | 28.6 °C | 112.01 mm |
| September | 16.7 °C | 24.9 °C | 102.62 mm |
| October | 10.4 °C | 18.4 °C | 104.39 mm |
| November | 4.7 °C | 12.3 °C | 86.61 mm |
| December | 0.4 °C | 6.9 °C | 105.16 mm |
| Annual | 8.9 °C | 17 °C | 1204.2 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |