Kauai essentially has two seasons: Luckily, the dry season encompasses those sweet spot months in spring and fall. The wet season begins in late fall and runs through winter. Both seasons are warm. Temperatures on land range from 70 to 85 and between 70 and 80 in the ocean, year round. You will not ever experience a cold snap on. May is generally considered one of the best times of year to go to kauai, as the month falls in a sweet spot between high seasons for tourism and during one of the best periods of weather on the island. Levels of tourism are still low before the peak in the summer, making it a great time for sightseeing or visiting some of kauai. Step off the plane and feel the warm embrace of kauai with average yearly temperatures ranging between 84 and 69 degrees. Ocean temperatures are also perfect ranging from 71 to 81 degrees year round.