Bananas are tropical fruits. Bananas are fruits that grow at an annual average temperature of 21 degrees Celsius. Bananas rarely grow at an annual average temperature of 21 degrees Celsius. That is to say, the environment with the lowest annual average temperature for banana growth is the environment with an annual average temperature of 21 degrees Celsius. The four islands in Japan, namely, the four islands in Japan, The four islands in Japan are listed in the order of Hokkaido, Honshu, Shikoku and Kyushu from north to south. The average annual temperature of the four islands in Japan is between 7-19 ℃, 2 ℃ less than the average annual temperature suitable for banana growth