September in Kastamonu averages a daily high of 24.2°C with nights around 9.3°C. Expect roughly 7.9 wet days totalling 41.4mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Kastamonu is July–October.
Based on KASTAMONU, TU (1.4km), 1995–2024. 18 years of September data.