October in Oshawa averages a daily high of 14.1°C with nights around 6.2°C. Expect roughly 13.2 wet days totalling 81.1mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Oshawa is June–September.
Based on OSHAWA WPCP, ON CA (3.9km), 1995–2024. 23 years of October data.