Castle Hayne, North Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11.2 °C (low) to 23.4 °C (high). Annual precipitation averages 1539.5 Millimeters. Castle Hayne is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 0.9 °C | 13.8 °C | 97.79 mm |
| February | 1.9 °C | 15.3 °C | 89.66 mm |
| March | 5.2 °C | 18.9 °C | 100.33 mm |
| April | 10.2 °C | 23.4 °C | 86.61 mm |
| May | 15.1 °C | 27.2 °C | 109.73 mm |
| June | 19.7 °C | 30.5 °C | 144.02 mm |
| July | 21.8 °C | 32.2 °C | 174.24 mm |
| August | 21 °C | 31.3 °C | 196.09 mm |
| September | 18.1 °C | 28.8 °C | 235.2 mm |
| October | 11.6 °C | 24.3 °C | 119.89 mm |
| November | 5.7 °C | 19.4 °C | 89.92 mm |
| December | 2.6 °C | 15.4 °C | 96.01 mm |
| Annual | 11.2 °C | 23.4 °C | 1539.49 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 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 | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |