What is Hawaii’s Weather like in Summer?  June, July, and August?  It’s hot!  On the East and North shores of all the islands it may be a bit cooler (like 80 F) but on the south and West sides it will generally be between 85 degrees and 90 degrees and very humid.

You are going to want to hit all activities that aren’t in the water early in the morning or once the sun is starting to go down.  Honestly, because we are very fair skinned, we would always try to stay indoors from the hours of about 12 to 4 pm, otherwise we were burning, sunscreen or not.

The heat and humidity are so much they will zap your energy in the middle of the day anyway – bring lots of water and try to have some to pour on your head too.

Generally, June, July, and August are the months of least rainfall everywhere in all of Hawaii.  Even Hilo may only have a few inches during these months.  I’ve been through summer droughts when the Hilo side of the Big Island of Hawaii, generally a very wet area, got almost no rain and all our grass died.

The highest temperature on record in the Aloha State is 100 degrees F, on August 27, 1931 in Pahala on the Big Island. The lowest temperature is 12 degrees F, recorded at the 13,770-foot elevation level of Mauna Kea on the Big Island on May 17, 1979. Hawaii is the only state in America never to have recorded a below-zero temperature.

Aloha-Hawaii.com: Hawaii Weather