May in Milwaukee averages a daily high of 18.7°C with nights around 8.6°C. Expect roughly 12 wet days totalling 94.7mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Milwaukee is June–September.
Based on MILWAUKEE MITCHELL AIRPORT, WI US (9.3km), 1995–2024. 30 years of May data.