Huntsville, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 14 °C (low) to 25.8 °C (high). Annual precipitation averages 1266.5 Millimeters. Huntsville is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.2 °C | 15.8 °C | 109.22 mm |
| February | 6.2 °C | 17.9 °C | 85.6 mm |
| March | 9.7 °C | 21.8 °C | 100.08 mm |
| April | 13.4 °C | 25.6 °C | 98.55 mm |
| May | 18.2 °C | 29.4 °C | 117.09 mm |
| June | 21.8 °C | 32.8 °C | 121.67 mm |
| July | 23.1 °C | 34.3 °C | 78.74 mm |
| August | 22.8 °C | 34.9 °C | 97.03 mm |
| September | 19.8 °C | 31.8 °C | 99.06 mm |
| October | 14.3 °C | 27 °C | 127 mm |
| November | 8.9 °C | 21.1 °C | 118.11 mm |
| December | 5.1 °C | 16.6 °C | 114.3 mm |
| Annual | 14 °C | 25.8 °C | 1266.45 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |