Highland Beach, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10 °C (low) to 18.3 °C (high). Annual precipitation averages 1147.3 Millimeters. Highland Beach 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 | 6.1 °C | 79.76 mm |
| February | -1.2 °C | 7.3 °C | 68.83 mm |
| March | 2.6 °C | 11.6 °C | 105.66 mm |
| April | 8.3 °C | 17.7 °C | 86.11 mm |
| May | 13.8 °C | 22.6 °C | 104.65 mm |
| June | 19.1 °C | 27.6 °C | 108.71 mm |
| July | 22.1 °C | 30.1 °C | 111 mm |
| August | 21.1 °C | 29.2 °C | 101.85 mm |
| September | 17.7 °C | 25.7 °C | 111 mm |
| October | 11.3 °C | 19.6 °C | 97.79 mm |
| November | 5.5 °C | 13.6 °C | 77.47 mm |
| December | 0.9 °C | 8.4 °C | 94.49 mm |
| Annual | 10 °C | 18.3 °C | 1147.32 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 |