May in Luleå averages a daily high of 12.5°C with nights around 3.3°C. Expect roughly 9 wet days totalling 38.1mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Luleå is June–August.
Based on LULEA BERGNASET, SW (2.1km), 1995–2024. 18 years of May data.