May in Burien averages a daily high of 18.4°C with nights around 8.9°C. Expect roughly 11.3 wet days totalling 49.1mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Burien is July–August.
Based on SEATTLE TACOMA AIRPORT, WA US (3.8km), 1995–2024. 30 years of May data.