June in Oshawa averages a daily high of 22.7°C with nights around 13.6°C. Expect roughly 11.4 wet days totalling 94.1mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Oshawa is June–September.
Based on OSHAWA WPCP, ON CA (3.9km), 1995–2024. 25 years of June data.