Flower Mound, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 13.1 °C (low) to 24.8 °C (high). Annual precipitation averages 969.3 Millimeters. Flower Mound 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 | 1.5 °C | 13.3 °C | 63.25 mm |
| February | 3.7 °C | 15.7 °C | 68.58 mm |
| March | 7.9 °C | 19.7 °C | 83.82 mm |
| April | 12.3 °C | 24.3 °C | 86.87 mm |
| May | 17.7 °C | 28.5 °C | 117.35 mm |
| June | 22.2 °C | 33 °C | 96.77 mm |
| July | 24.2 °C | 35.5 °C | 56.9 mm |
| August | 23.9 °C | 35.6 °C | 57.91 mm |
| September | 19.8 °C | 31.7 °C | 77.47 mm |
| October | 13.4 °C | 26.1 °C | 110.24 mm |
| November | 7.4 °C | 19.3 °C | 72.9 mm |
| December | 2.7 °C | 14.4 °C | 77.22 mm |
| Annual | 13.1 °C | 24.8 °C | 969.28 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| 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 |