September in Schiedam averages a daily high of 19.7°C with nights around 11°C. Expect roughly 13.5 wet days totalling 89.1mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Schiedam is May–September.
Based on ROTTERDAM, NL (6.1km), 1995–2024. 30 years of September data.