If you spend Christmas on Kos you will find the island peaceful and serene, with people enjoying traditions and life without the madding tourist crowds.
Pserimos is one of the most interesting attractions to see when you are vacationing on Kos. Although the island is easier accessible from Kalimnos, there are still boats ready to take you to the streetless island if you plan ahead.
Although according to the calendar October is an autumn month, on Kos, is the last month of the summer. The average temperature highs stay around 22ºC in October, with more rain than September, yet the weather is pleasant enough especially for travelers who enjoy hiking, mountain biking, and other outdoor activities that are uncomfortable under the hot summer sun from June to August.
If you plan to vacation on Kos in September, the island is still welcoming and warm, as the bulk of the tourist crowds subsides.