Grantsboro, North Carolina has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 52.8 °F (low) to 73.4 °F (high). Annual precipitation averages 56.7 Inches. Grantsboro is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 34.8 °F | 55.5 °F | 3.89 in. |
| February | 36.5 °F | 58.4 °F | 3.36 in. |
| March | 42.1 °F | 64.8 °F | 3.64 in. |
| April | 50.9 °F | 74.0 °F | 3.33 in. |
| May | 59.5 °F | 80.5 °F | 4.36 in. |
| June | 67.7 °F | 86.9 °F | 5.39 in. |
| July | 71.3 °F | 89.7 °F | 6.78 in. |
| August | 70.2 °F | 87.9 °F | 7.4 in. |
| September | 65.5 °F | 83.5 °F | 7.08 in. |
| October | 54.2 °F | 75.1 °F | 4.01 in. |
| November | 43.7 °F | 65.6 °F | 3.75 in. |
| December | 37.7 °F | 58.6 °F | 3.73 in. |
| Annual | 52.8 °F | 73.4 °F | 56.72 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |