Kos enjoys a Mediterranean climate with a year-round average of 77°F, the summer months are hot and dry and rainfall virtually nonexistent. Highs of more than 90°F are not unknown in summer. August brings the northern 'meltemi' wind to relieve the heat and temperatures ease off in September.

Many tourists visit Kos in May or October when it is still warm, sunny and the nights are relatively cool. December has the highest rainfall but there are still plenty of days of sunshine.

From April to September, is the main summer season in Kos. The weather is hot and sunny with little very little rain seen.

Lasts from October to March, it can get chilly, especially at night, but temperatures rarely drop below freezing.