April in Waukesha averages a daily high of 13.5°C with nights around 2.2°C. Expect roughly 10.8 wet days totalling 91.6mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Waukesha is June–September.
Based on WAUKESHA WWTP, WI US (2.2km), 1995–2024. 20 years of April data.