May in Plano averages a daily high of 28.2°C with nights around 17.8°C. Expect roughly 9.7 wet days totalling 137.7mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Plano is March–April.
Based on RICHARDSON, TX US (4.9km), 1995–2024. 18 years of May data.