May in Seinäjoki averages a daily high of 15.1°C with nights around 3.3°C. Expect roughly 10.1 wet days totalling 48.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Seinäjoki is June–August.
Based on SEINAJOKI PELMAA, FI (23.3km), 1995–2024. 30 years of May data.