July in Ottawa South averages a daily high of 27°C with nights around 16°C. Expect roughly 11.6 wet days totalling 95.1mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Ottawa South is May–September.
Based on OTTAWA CDA, ON CA (2.5km), 1995–2024. 29 years of July data.