May in Solna averages a daily high of 16.4°C with nights around 5.8°C. Expect roughly 11 wet days totalling 49.2mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Solna is June–August.
Based on STOCKHOLM BROMMA, SW (2.9km), 1995–2024. 30 years of May data.