Southport, North Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 13.5 °C (low) to 22.4 °C (high). Annual precipitation averages 1499.1 Millimeters. Southport is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.3 °C | 13 °C | 96.77 mm |
| February | 4 °C | 14.3 °C | 89.92 mm |
| March | 7.5 °C | 17.7 °C | 100.08 mm |
| April | 12.6 °C | 22.2 °C | 86.36 mm |
| May | 17.3 °C | 25.9 °C | 108.71 mm |
| June | 21.7 °C | 29.3 °C | 129.54 mm |
| July | 23.6 °C | 30.2 °C | 172.21 mm |
| August | 22.9 °C | 30.6 °C | 178.05 mm |
| September | 20.2 °C | 27.9 °C | 223.27 mm |
| October | 14.4 °C | 23.8 °C | 124.97 mm |
| November | 8.8 °C | 18.8 °C | 94.23 mm |
| December | 5.1 °C | 14.9 °C | 95 mm |
| Annual | 13.5 °C | 22.4 °C | 1499.11 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |