Although typhoon season is supposed to run June through November, on Okinawa you need to stay alert during the offseason as well. Since 1951, there have been six typhoons that have come close to Japan after November. Two of the six came close to Okinawa - in 1984 and 2004. The latter of the two was the year when Okinawa was hit with 15 typhoons, which is the most in a single year.