Crownsville, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.1 °C (low) to 18.9 °C (high). Annual precipitation averages 1182.6 Millimeters. Crownsville 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 Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.4 °C | 6.3 °C | 80.26 mm |
| February | -2.7 °C | 7.8 °C | 70.87 mm |
| March | 1.2 °C | 12.3 °C | 106.17 mm |
| April | 6.8 °C | 18.8 °C | 88.39 mm |
| May | 12.2 °C | 23.6 °C | 108.46 mm |
| June | 17.4 °C | 28.4 °C | 114.05 mm |
| July | 20.1 °C | 30.8 °C | 116.84 mm |
| August | 19.2 °C | 29.9 °C | 100.84 mm |
| September | 15.4 °C | 26.3 °C | 118.87 mm |
| October | 8.7 °C | 19.9 °C | 100.84 mm |
| November | 2.9 °C | 13.8 °C | 80.26 mm |
| December | -1 °C | 8.6 °C | 96.77 mm |
| Annual | 8.1 °C | 18.9 °C | 1182.62 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| 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 7b : -15°C to -12.2°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |