Water temp is between 77-82 degrees year-round, depending on depth and topography. Because of the high heat output from the body during active swimming (such as with dolphins), a water temperature of 72 to 75°F is acceptable. With a lower level of activity (snorkeling), a water temperature of 75 to 80°F may be desirable. Ocean temps in Hawaii are normally around 75-76 degrees in the winter and up to 82 degrees in the summer/fall.
A shallow sandy beach like Makua, will be warmer (radiation over sand) than the deeper reef over Makaha. Makaha also has fresh water influx which is cooler. It’s usually coldest in spring as the ocean cools over the winter and warmest in late fall as the sea heats over summer.
When you are wet, you may get chilly onboard from the wind. Don’t forget a towel, they are quite warming when wrapped around you. A rash guard is always a good idea both to protect you from the sun and from any little “stingers” in the water. If you get cold easy in the water, you can always rent a wetsuit the day before at one of the dive shops around the island, such as:
Snorkel Bob’s – https://snorkelbob.com
700 Kapahulu Ave. Honolulu, HI 96816
(808) 735-7944
Aaron’s Dive Shop – http://www.aaronsdiveshop.com
307 Hahani Street Kailua, Hawaii
(808) 262-2333
Based on our historical data over a period of ten years, the warmest water in Waianae was recorded in 2019 and was 81.3°F, and the coldest was recorded in 2012 at 77.7°F. Waianae water temperature is therefore suitable for comfortable swimming all year round. The average water temperature in Waianae in winter reaches 77°F, in spring 77°F, in summer the average temperature rises to 79.9°F, and in autumn it is 80.6°F.
