May in Winnipeg averages a daily high of 18°C with nights around 6.9°C. Expect roughly 10.5 wet days totalling 70.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Winnipeg is June–September.
Based on WINNIPEG THE FORKS, MB CA (1km), 1995–2024. 23 years of May data.