Brandywine, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.2 °C (low) to 19.6 °C (high). Annual precipitation averages 1153.4 Millimeters. Brandywine 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 | -3.1 °C | 6.9 °C | 78.74 mm |
| February | -2.2 °C | 8.7 °C | 70.87 mm |
| March | 1.5 °C | 13.3 °C | 99.57 mm |
| April | 7.1 °C | 19.8 °C | 83.57 mm |
| May | 12.3 °C | 24.5 °C | 108.71 mm |
| June | 17.4 °C | 29 °C | 111.25 mm |
| July | 20.1 °C | 31.3 °C | 109.73 mm |
| August | 19.2 °C | 30.4 °C | 98.81 mm |
| September | 15.5 °C | 26.8 °C | 109.98 mm |
| October | 8.8 °C | 20.4 °C | 100.58 mm |
| November | 3.1 °C | 14.4 °C | 84.07 mm |
| December | -0.8 °C | 9.1 °C | 97.54 mm |
| Annual | 8.2 °C | 19.6 °C | 1153.42 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 | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |