May in Lewisville averages a daily high of 28.8°C with nights around 17°C. Expect roughly 9.6 wet days totalling 114.8mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Lewisville is March–April.
Based on GRAPEVINE DAM, TX US (12.1km), 1995–2024. 20 years of May data.