Granbury, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12.1 °C (low) to 25.6 °C (high). Annual precipitation averages 908.1 Millimeters. 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 | 0.7 °C | 14.7 °C | 52.07 mm |
| February | 2.9 °C | 16.8 °C | 63.75 mm |
| March | 7.2 °C | 20.9 °C | 84.84 mm |
| April | 11.4 °C | 25.5 °C | 76.2 mm |
| May | 16.8 °C | 29.2 °C | 116.33 mm |
| June | 21.3 °C | 33.6 °C | 101.09 mm |
| July | 23.2 °C | 36 °C | 44.45 mm |
| August | 22.7 °C | 36.3 °C | 69.34 mm |
| September | 18.6 °C | 32.2 °C | 77.22 mm |
| October | 12.4 °C | 26.7 °C | 99.57 mm |
| November | 6.5 °C | 19.9 °C | 66.04 mm |
| December | 1.7 °C | 15.4 °C | 57.15 mm |
| Annual | 12.1 °C | 25.6 °C | 908.05 mm |
| 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 : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |