Granbury, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 53.8 °F (low) to 78.1 °F (high). Annual precipitation averages 35.8 Inches. Granbury 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 | 33.3 °F | 58.4 °F | 2.05 in. |
| February | 37.3 °F | 62.2 °F | 2.51 in. |
| March | 44.9 °F | 69.6 °F | 3.34 in. |
| April | 52.6 °F | 77.9 °F | 3.0 in. |
| May | 62.2 °F | 84.6 °F | 4.58 in. |
| June | 70.4 °F | 92.4 °F | 3.98 in. |
| July | 73.7 °F | 96.8 °F | 1.75 in. |
| August | 72.9 °F | 97.3 °F | 2.73 in. |
| September | 65.4 °F | 89.9 °F | 3.04 in. |
| October | 54.3 °F | 80.0 °F | 3.92 in. |
| November | 43.7 °F | 67.9 °F | 2.6 in. |
| December | 35.0 °F | 59.7 °F | 2.25 in. |
| Annual | 53.8 °F | 78.1 °F | 35.75 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 | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |