A nice post with a guide to Hawaii's summer fruits from a newish blog, Beat of Hawaii. Some of the information is not correct but it's generally good. A few corrections.

Mangoes are available for a month in the summer -- Actually, a lot of growers have figured out how to run double fruiting trees. Mangos are available a lot more than just in the June-July stretch. Hadens are most common in that period but Tommy Atkins can be had almost year round and are grown in several places. Mango growers in Waianae run basically full tilt.

Hawaii bananas are a summer fruit -- Not true. Also called apple bananas, these are available year round, easy. So you can look for them whenver. They look like dwarf bananas. That said, you can also get Cavendish bananas that are from Hawaii, as well -- the longer versions that you see on the Mainland. You cannot get Apple bananas on the Mainland so definitely eat them here.

—Alex, 07/22/08