Glassboro, New Jersey has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.5 °C (low) to 18.1 °C (high). Annual precipitation averages 1220.7 Millimeters. Glassboro 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. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.1 °C | 5.2 °C | 99.57 mm |
| February | -3.3 °C | 6.6 °C | 74.17 mm |
| March | 0.3 °C | 10.8 °C | 116.84 mm |
| April | 6.1 °C | 17.7 °C | 92.2 mm |
| May | 11.3 °C | 23.1 °C | 97.03 mm |
| June | 16.6 °C | 28.1 °C | 110.49 mm |
| July | 19.7 °C | 30.3 °C | 120.9 mm |
| August | 18.7 °C | 29.3 °C | 118.11 mm |
| September | 15 °C | 25.8 °C | 104.14 mm |
| October | 8.3 °C | 19.2 °C | 101.35 mm |
| November | 2.7 °C | 13.2 °C | 76.96 mm |
| December | -1.2 °C | 7.9 °C | 108.97 mm |
| Annual | 7.5 °C | 18.1 °C | 1220.73 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| 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 | Cfa - Humid Subtropical Climate |