Calverton, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.7 °C (low) to 19.1 °C (high). Annual precipitation averages 1174.5 Millimeters. Calverton is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.6 °C | 6.3 °C | 79.76 mm |
| February | -2.7 °C | 8.1 °C | 70.36 mm |
| March | 0.9 °C | 12.8 °C | 102.62 mm |
| April | 6.4 °C | 19.2 °C | 89.66 mm |
| May | 11.9 °C | 23.9 °C | 114.55 mm |
| June | 16.8 °C | 28.6 °C | 117.35 mm |
| July | 19.5 °C | 31 °C | 112.27 mm |
| August | 18.6 °C | 30 °C | 94.23 mm |
| September | 14.9 °C | 26.3 °C | 117.09 mm |
| October | 8.3 °C | 19.9 °C | 99.57 mm |
| November | 2.6 °C | 13.9 °C | 81.28 mm |
| December | -1.2 °C | 8.6 °C | 95.76 mm |
| Annual | 7.7 °C | 19.1 °C | 1174.5 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 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 |