Koper's winters are cool and occasionally cold, with temperatures often below freezing but rarely staying that way for extended periods. Spring brings gradual warming, with March typically being the first month to see consistent highs above 20 degrees Celsius. Summers are warm and sunny, with July usually being the hottest month, though not excessively so. Autumn is mild, with temperatures generally pleasant in September and October, although it can cool down quickly towards November. Winters return with temperatures dropping to near-freezing again by December.