November in Barreiro averages a daily high of 18°C with nights around 11.9°C. Expect roughly 12 wet days totalling 139.5mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Barreiro is May–September.
Based on LISBOA GEOFISICA, PO (9km), 1995–2024. 25 years of November data.