Due to the large North South extension of the country, the climate varies strongly in different regions. The climate in most of the major cities, including Tokyo, is temperate to subtropic and consists of four seasons. The winter is mild and the summer is hot and humid. There is a rainy season in early summer, and typhoons hit parts of the country every year during late summer. The climate of the northern island of Hokkaido and the Sea of Japan coast is colder, and snow falls in large amounts. In Okinawa, on the other hand, the mean temperature of January is a warm 17 degrees Celsius.