Brandywine, West Virginia has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.5 °C (low) to 18.1 °C (high). Annual precipitation averages 901.7 Millimeters. Brandywine is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.1 °C | 5.6 °C | 55.63 mm |
| February | -5.1 °C | 7.3 °C | 44.96 mm |
| March | -1.6 °C | 11.7 °C | 75.18 mm |
| April | 3.3 °C | 18.5 °C | 78.23 mm |
| May | 8.6 °C | 23.1 °C | 102.87 mm |
| June | 13.4 °C | 27.4 °C | 83.57 mm |
| July | 15.6 °C | 29.4 °C | 102.36 mm |
| August | 14.8 °C | 28.7 °C | 92.2 mm |
| September | 11.1 °C | 25.6 °C | 87.63 mm |
| October | 4.8 °C | 19.6 °C | 57.66 mm |
| November | -0.7 °C | 13.1 °C | 62.23 mm |
| December | -3.8 °C | 7.7 °C | 59.18 mm |
| Annual | 4.5 °C | 18.1 °C | 901.7 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| 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 | Dfb - Humid Continental Mild Summer, Wet All Year |