September in Bellingham averages a daily high of 20°C with nights around 10.3°C. Expect roughly 9.3 wet days totalling 53.3mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Bellingham is July–August.
Based on BELLINGHAM 3 SSW, WA US (5.1km), 1995–2024. 28 years of September data.