Duncanville, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 55.3 °F (low) to 76.3 °F (high). Annual precipitation averages 40.2 Inches. Duncanville 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. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.5 °F | 56.5 °F | 2.69 in. |
| February | 38.9 °F | 60.1 °F | 2.81 in. |
| March | 46.3 °F | 67.6 °F | 3.54 in. |
| April | 53.8 °F | 75.4 °F | 3.73 in. |
| May | 63.3 °F | 82.8 °F | 4.67 in. |
| June | 71.3 °F | 90.7 °F | 3.99 in. |
| July | 74.4 °F | 94.8 °F | 2.2 in. |
| August | 74.2 °F | 95.5 °F | 2.19 in. |
| September | 67.1 °F | 88.8 °F | 3.29 in. |
| October | 55.7 °F | 78.2 °F | 4.9 in. |
| November | 45.6 °F | 66.7 °F | 2.99 in. |
| December | 37.1 °F | 57.9 °F | 3.23 in. |
| Annual | 55.3 °F | 76.3 °F | 40.23 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 30-40 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 |