May in Irun averages a daily high of 21°C with nights around 12.4°C. Expect roughly 15 wet days totalling 124.2mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Irun is May–October.
Based on SAN SEBASTIAN FUENTERRABIA, SP (2.4km), 1995–2024. 27 years of May data.