Smith Island, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11.3 °C (low) to 19 °C (high). Annual precipitation averages 1150.4 Millimeters. Smith 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 | -0.1 °C | 7 °C | 80.77 mm |
| February | 0.2 °C | 8.1 °C | 75.69 mm |
| March | 3.6 °C | 11.6 °C | 105.41 mm |
| April | 9.2 °C | 18.3 °C | 84.84 mm |
| May | 14.7 °C | 23.2 °C | 91.44 mm |
| June | 20.2 °C | 27.8 °C | 102.36 mm |
| July | 23 °C | 30.6 °C | 112.52 mm |
| August | 22.3 °C | 29.7 °C | 117.35 mm |
| September | 19.3 °C | 26.8 °C | 107.95 mm |
| October | 13.1 °C | 20.9 °C | 102.36 mm |
| November | 7 °C | 14.6 °C | 76.96 mm |
| December | 2.7 °C | 9.6 °C | 92.71 mm |
| Annual | 11.3 °C | 19 °C | 1150.36 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |