Zephyr, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11.3 °C (low) to 25.1 °C (high). Annual precipitation averages 769.9 Millimeters. Zephyr 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 | 0.3 °C | 14.9 °C | 42.16 mm |
| February | 2.7 °C | 17.1 °C | 52.83 mm |
| March | 6.9 °C | 20.8 °C | 65.28 mm |
| April | 10.6 °C | 25.1 °C | 59.18 mm |
| May | 15.7 °C | 28.7 °C | 105.66 mm |
| June | 20.1 °C | 32.6 °C | 98.04 mm |
| July | 21.6 °C | 34.7 °C | 49.53 mm |
| August | 21.4 °C | 34.8 °C | 54.86 mm |
| September | 17.7 °C | 31.2 °C | 71.37 mm |
| October | 11.4 °C | 26.1 °C | 79.25 mm |
| November | 5.6 °C | 19.8 °C | 51.56 mm |
| December | 1.1 °C | 15.3 °C | 40.13 mm |
| Annual | 11.3 °C | 25.1 °C | 769.85 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| 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 |