Garrett, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12.8 °C (low) to 24.9 °C (high). Annual precipitation averages 1052.6 Millimeters. Garrett is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.9 °C | 13.8 °C | 81.28 mm |
| February | 3.9 °C | 16 °C | 78.23 mm |
| March | 7.9 °C | 20 °C | 94.74 mm |
| April | 11.9 °C | 24.3 °C | 95 mm |
| May | 17.2 °C | 28.4 °C | 114.81 mm |
| June | 21.5 °C | 32.8 °C | 101.35 mm |
| July | 23.2 °C | 35.2 °C | 45.97 mm |
| August | 23.1 °C | 35.6 °C | 68.33 mm |
| September | 19.2 °C | 31.9 °C | 81.03 mm |
| October | 12.9 °C | 26.3 °C | 124.97 mm |
| November | 7.4 °C | 19.7 °C | 77.98 mm |
| December | 2.9 °C | 14.7 °C | 88.9 mm |
| Annual | 12.8 °C | 24.9 °C | 1052.59 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 30-40 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 |