January in Irun averages a daily high of 12.9°C with nights around 5.7°C. Expect roughly 16.4 wet days totalling 185.7mm. Demanding conditions — pack for it and plan indoor options.
Across the year, the best time to visit Irun is May–October.
Based on SAN SEBASTIAN FUENTERRABIA, SP (2.4km), 1995–2024. 18 years of January data.