Japan Climate [edit this]
Overview of Japan's climate
Japanese are proud of their four seasons (and a surprising number believe the phenomenon is unique to Japan), but the discerning tourist should try to aim for two of them.
Spring is probably the best time of year to be in Japan. The temperatures are warm but not hot, there's not too much rain, and March-April brings the justly famous cherry blossoms and is a time of revelry and festivals. Just watch out for Golden Week (April 27 to May 6), the longest holiday of the year, when everybody travels and everything is booked full.
Summer starts with a dreary rainy season in June and turns into a steam bath in July-August, with extreme humidity and the temperature heading as high as 40°C. O-Bon (mid-August), when everybody is on the road again, is probably the worst possible time to visit. Avoid, or do as the Japanese do and head to northern Hokkaido or the mountains of Chubu and Tohoku to escape.
Autumn - Fall, starting in September, is a close second to spring. Temperatures become more tolerable, fair days are common and fall colors can be just as impressive as cherry blossoms.
Winter is a good time to go skiing or hot-spring hopping, but as the Japanese have yet to figure out the wonders of central heating, it's often miserably cold indoors. Heading south to Okinawa provides some relief. Also watch out for New Years (December 29 to January 3), the only days of the year when everything in the country shuts down.
Edit by: Vincent