Average Ocean Temperatures for Hawaii

The water's warm enough to swim in at any time of the year on beaches in Hawaii. The Pacific islands' average ocean temperatures for each month are listed below in degrees Fahrenheit and degrees Celsius.

At Honolulu on Oahu, the ocean stays as warm as a heated swimming pool all year long.

Ocean temperatures do differ by a few degrees throughout the Hawaiian Islands, though. The water off Honolulu, for instance, is typically 5 °F (3 °C) warmer than at Hilo on the Big Island.

Yet Hawaii's ocean temperatures don't vary much from month to month. The water fluctuates by only 5 °F over the year off Honolulu. At Hilo, the temperature stays even steadier, varying just 3 °F (2 °C) annually.

The Pacific Ocean at both cities reaches its highest temperature in September and October. By March, Hilo's water has dropped to its coldest of the year, at 71 °F (21.7 °C), on average. The water during winter at Honolulu's beaches typically maintains a steady 76 °F (24 °C) from January through to April.

Average ocean temperature in °F

	Honolulu	Hilo
January	76	72
February	76	72
March	76	71
April	76	72
May	78	72
June	79	74
July	80	74
August	80	75
September	81	75
October	81	75
November	79	74
December	77	73
Annual	78	73

Average water temperature in °C

	Honolulu	Hilo
January	24	22
February	24	22
March	24	22
April	24	22
May	26	22
June	26	23
July	27	23
August	27	24
September	27	24
October	27	24
November	26	23
December	25	23
Annual	26	23