June in Sammamish averages a daily high of 21.4°C with nights around 11.6°C. Expect roughly 10.4 wet days totalling 41.3mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Sammamish is July–August.
Based on SEATTLE SAND POINT WEATHER FORECAST OFFICE, WA US (14km), 1995–2024. 28 years of June data.