April in Zagreb averages a daily high of 18.2°C with nights around 8.8°C. Expect roughly 11.1 wet days totalling 61mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Zagreb is April–October.
Based on ZAGREB GRIC, HR (0.3km), 1995–2024. 28 years of April data.