May in Bellingham averages a daily high of 18°C with nights around 8°C. Expect roughly 11.3 wet days totalling 61.3mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Bellingham is July–August.
Based on BELLINGHAM 3 SSW, WA US (5.1km), 1995–2024. 29 years of May data.