Flower Mound experiences a Humid Subtropical climate (Köppen climate classification *Cfa*). The weather is heavily influenced by the warm, moist air from the Gulf of Mexico. Summers are typically hot and humid, with high temperatures frequently exceeding 100°F (38°C) in July and August. Winters are generally mild, with average highs in the 50s°F (10-15°C) and lows occasionally dropping below freezing.
Spring and autumn are considered the best times to visit, offering pleasant temperatures and vibrant natural color—especially the native wildflowers in April and May. As part of North Texas, Flower Mound is situated at the southern end of 'Tornado Alley.' The town is susceptible to severe spring thunderstorms, which can bring heavy rainfall, lightning, hail, and the occasional tornado. Snowfall is rare and generally light when it does occur.