Lewisville, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 13.3 °C (low) to 24.8 °C (high). Annual precipitation averages 977.9 Millimeters. Lewisville 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 | 1.8 °C | 13.3 °C | 63.5 mm |
| February | 3.8 °C | 15.8 °C | 69.6 mm |
| March | 8.2 °C | 19.8 °C | 87.63 mm |
| April | 12.5 °C | 24.4 °C | 88.65 mm |
| May | 17.9 °C | 28.5 °C | 118.62 mm |
| June | 22.4 °C | 32.9 °C | 95.76 mm |
| July | 24.3 °C | 35.6 °C | 57.66 mm |
| August | 24.1 °C | 35.5 °C | 57.4 mm |
| September | 20.1 °C | 31.7 °C | 73.66 mm |
| October | 13.7 °C | 26.2 °C | 112.52 mm |
| November | 7.7 °C | 19.3 °C | 74.17 mm |
| December | 3 °C | 14.6 °C | 78.74 mm |
| Annual | 13.3 °C | 24.8 °C | 977.91 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 |