Petty, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11.4 °C (low) to 23.6 °C (high). Annual precipitation averages 1146.6 Millimeters. Petty is located in USDA Plant Hardiness Zone 8a. 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 | 0.1 °C | 12 °C | 76.45 mm |
| February | 2.1 °C | 14.3 °C | 85.34 mm |
| March | 6.3 °C | 18.7 °C | 101.85 mm |
| April | 10.4 °C | 23.1 °C | 97.79 mm |
| May | 15.9 °C | 27.2 °C | 135.13 mm |
| June | 20.4 °C | 31.7 °C | 99.31 mm |
| July | 22.4 °C | 34.3 °C | 72.14 mm |
| August | 21.9 °C | 34.5 °C | 64.01 mm |
| September | 18 °C | 30.8 °C | 92.2 mm |
| October | 11.5 °C | 24.9 °C | 119.89 mm |
| November | 5.8 °C | 18.3 °C | 99.06 mm |
| December | 1.4 °C | 13.1 °C | 103.38 mm |
| Annual | 11.4 °C | 23.6 °C | 1146.55 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 8a : -12.2°C to -9.4°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 |