According to data from the National Oceanic Atmospheric Association (NOAA), the warmest water off Honolulu can be found from July to September—averaging 80 to 81 degrees Fahrenheit. However, Honolulu water temperatures drop to only 76 degrees in January, according to NOAA.
Referencing data for Honolulu, Oahu from NOAA, ocean temperatures range from 76°F ( 24.4°C ) to 81°F ( 27.2°C ). The following chart shows Honolulu’s monthly water temperature average.
Though January is one of the cooler months, you can still swim in the ocean. For more details see our Hawaii ocean water temperatures article.
Bet you didn’t even know that is snows in Hawaii ! Water temperatures are around 74 degrees so swimming is a year round activity here in Hawaii . If you ‘re looking into boating, snorkeling, surfing or any other Hawaii activity this winter , be sure to book as soon as possible!
Certain ocean conditions can make Hawaii’s beaches hazardous for swimming — namely high surf, dangerous shorebreaks and strong currents. While Hawaii has one of the nation’s best lifeguard systems, some remote beaches do not have lifeguard towers. It is not recommended to swim at a beach that has no lifeguard tower.
There are four shark species common in Hawai’i. They are the white reef tip, black reef tip, sandbar and scalloped hammerhead shark. Occasionally there are tiger shark sightings. Tiger sharks are considered aggressive to humans.
As a general rule, Hawaiian waters average 77 degrees in the wintertime to 82 degrees in the summertime. Now, compared to the U.S. West Coast, Hawaiian waters are definitely much warmer (10-20 degrees warmer ) than the waters off Southern California. No comparison really for the U.S. West Coast.
Maui – The best sunshine is on West and South Maui . Oahu – Basically the southern and southwestern end of the island is the driest. Big Island – The Kohala Coast is super sunny year round where it only receives around 10 inches of rain each year.
It has warm weather throughout the year, including January . When visiting at this time , you will see tropical flowers in bloom and can bask in balmy tropical temperatures in the low 80s. The only downside is that January follows Hawaii’s rainiest month, December. So, you will see slightly higher chances of rain.
Shorts and t-shirt, mostly. Certainly nothing more than chinos/capris and a lightweight, long-sleeved shirt/top. You’ll want to bring a light jacket or sweater; evenings can be cool. Rain probably won’t be an all-day affair, but the north shore will certainly be cooler, and it gets more rain in winter.
Hawaii’s Weather When it’s raining on one side of an island in Hawaii , though, the sun is usually shining on another, a short drive away. However, if the priority is to avoid heavy downpours in traditionally fun-in-the-sun locations such as Waikiki, Poipu, Kona and Kihei, the worst time to go is November through April.
Of course, we all know that tiger sharks are present in Hawaiian waters all year long. It’s just the late summer and fall months that seem to be the peak in attacks.
While many vacations are five to seven days long, we recommend staying for at least 10 days to enjoy your Hawaiian vacation. The time change is difficult to adjust to at first and takes about 3 days to get fully acclimated. So, allowing a couple days to get over the jet lag is important.