Weather in September
's weather in September
heralds the arrival of autumn, with a slight diminution in sea temperature to 23.3°C (73.9°F). The receding heat signals the end of the hot summer days, adding a hint of freshness in the air. Yet, the lingering warmth and extended daylight hours make September an appealing month for late summer visitors. The city maintains its vibrant atmosphere, as the summer slowly gives way to the soft touch of autumn.
In September, the average sea temperature in Koper, Slovenia
, is 23.3°C (73.9°F).Note
: The cold tolerance of an individual, along with sunshine, wind, and the temperature of the environment, affects the enjoyment of swimming in 23.3°C (73.9°F) waters. (Olympic swimmers participate in waters ranging from 25°C (77°F) to 28°C (82.4°F).)
In Koper, the average length of the day in September is 12h and 32min.
On the first day of the month, sunrise is at 06:27 and sunset at 19:42. On the last day of September, sunrise is at 07:02 and sunset at 18:47 CEST.