Terrell, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 54.5 °F (low) to 75.9 °F (high). Annual precipitation averages 42.2 Inches. Terrell 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 | 34.8 °F | 55.8 °F | 2.88 in. |
| February | 38.4 °F | 59.9 °F | 3.13 in. |
| March | 45.6 °F | 67.4 °F | 3.89 in. |
| April | 53.0 °F | 75.0 °F | 3.57 in. |
| May | 62.6 °F | 82.5 °F | 4.93 in. |
| June | 70.5 °F | 90.3 °F | 3.86 in. |
| July | 73.5 °F | 94.3 °F | 2.0 in. |
| August | 73.1 °F | 95.0 °F | 2.62 in. |
| September | 66.2 °F | 88.6 °F | 2.93 in. |
| October | 55.1 °F | 78.2 °F | 5.11 in. |
| November | 44.7 °F | 66.6 °F | 3.51 in. |
| December | 36.7 °F | 57.7 °F | 3.73 in. |
| Annual | 54.5 °F | 75.9 °F | 42.16 in. |
| 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 : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |