Broomes Island, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.3 °C (low) to 19.2 °C (high). Annual precipitation averages 1164.6 Millimeters. Broomes Island is located in USDA Plant Hardiness Zone 8a. 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 | -1.8 °C | 7.2 °C | 80.77 mm |
| February | -1.1 °C | 8.3 °C | 71.88 mm |
| March | 2.6 °C | 12.4 °C | 103.89 mm |
| April | 8.1 °C | 19.1 °C | 84.58 mm |
| May | 13.3 °C | 23.6 °C | 104.39 mm |
| June | 18.3 °C | 28.3 °C | 106.93 mm |
| July | 20.9 °C | 30.7 °C | 113.03 mm |
| August | 20 °C | 29.7 °C | 109.73 mm |
| September | 16.4 °C | 26.6 °C | 110.49 mm |
| October | 9.9 °C | 20.6 °C | 102.36 mm |
| November | 4.3 °C | 14.4 °C | 81.28 mm |
| December | 0.8 °C | 9.7 °C | 95.25 mm |
| Annual | 9.3 °C | 19.2 °C | 1164.58 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 8a : -12.2°C to -9.4°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 |