Derwood, Maryland has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 45.7 °F (low) to 64.9 °F (high). Annual precipitation averages 45.2 Inches. Derwood is located in USDA Plant Hardiness Zone 7b. 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 | 25.4 °F | 41.9 °F | 3.12 in. |
| February | 26.9 °F | 45.1 °F | 2.76 in. |
| March | 33.6 °F | 53.5 °F | 3.96 in. |
| April | 43.5 °F | 65.5 °F | 3.41 in. |
| May | 53.4 °F | 73.9 °F | 4.45 in. |
| June | 62.1 °F | 82.2 °F | 4.49 in. |
| July | 66.8 °F | 86.5 °F | 4.27 in. |
| August | 65.0 °F | 84.6 °F | 3.56 in. |
| September | 58.5 °F | 77.9 °F | 4.4 in. |
| October | 46.6 °F | 66.5 °F | 3.87 in. |
| November | 36.8 °F | 55.8 °F | 3.29 in. |
| December | 29.6 °F | 45.9 °F | 3.64 in. |
| Annual | 45.7 °F | 64.9 °F | 45.22 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |