April in Hoorn averages a daily high of 13.7°C with nights around 4.1°C. Expect roughly 10.9 wet days totalling 46.3mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Hoorn is June–September.
Based on BERKHOUT, NL (5.5km), 1995–2024. 26 years of April data.