April in Lisbon averages a daily high of 20.2°C with nights around 12.4°C. Expect roughly 9.6 wet days totalling 67.2mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Lisbon is May–September.
Based on LISBOA GEOFISICA, PO (0.9km), 1995–2024. 25 years of April data.