The state of Hawaii is a beautiful part of the US and a very desirable tourist destination for beach holidays. Many tourists from America and other countries visit the islands throughout the year to indulge in time on the beach, in the ocean, diving, and snorkeling. However, for many people wanting to travel to Hawaii, one essential question needs to be answered: is the water warm?
According to the NCEI and other charts, the waters of Hawaii are classified as reasonably warm. However, the temperature of ocean water varies for different Hawaiian islands. With this in mind, water temperatures of the ocean surrounding the Hawaiian Islands usually range from around 71°F to 83°F.
Though it seems the ocean waters of the Hawaiian Islands are relatively warm and unlikely to be considered freezing, some islands still have higher water temperatures than others. If you plan a trip to Hawaii, it is a good idea to consider the time of year you will visit these islands and which are the best based on temperature and your ability to swim and enjoy the beach.
Is Hawaii’s Water Warm?
According to the swimming and water index provided by My Weather 2, the ocean waters of Hawaii are most likely to range between “fairly warm” and “very warm.” This analysis means that, though not everyone will agree, and though there are areas with warmer waters, the Hawaiian beaches get considered to have warm ocean waters.
Hawaii can be a very nice area to swim, dive, snorkel, or enjoy the beach and the water, especially if you go to the warmer beaches and during the times of the year when the ocean water is warmer. The relatively high ocean water temperatures around the Hawaiian islands make it a comfortable place to enjoy since you can often spend long periods in the water without a problem.
What Are The Ocean Water Temperatures Of Hawaii’s Islands
Since many different islands form a part of the state of Hawaii, it is best to know what the water temperature would look like on each of these islands or areas of these islands. Since the most reliable information concerning the ocean water temperature is from a governmental source, the following are the ocean water temperatures found on the National Centers for Environmental Information website.
Honolulu Oahu Island
The average ocean water temperature of Honolulu Oahu Island ranges between 76°F and 81°F. The colder months with temperatures between 76°F and 78°F are January, February, March, April, and May. For the rest of the year, the temperatures will likely be 79°F and above for this specific area.
The months with the warmest ocean water temperature are September and October, meaning that these would be the ideal months to spend in this part of Hawaii if you want warmer water.
Hilo Hawaii Island
The ocean water temperature in this part of Hawaii does not usually go above 75°F, no matter the time of the year. Again, the coldest ocean water months are between January and May, with temperatures between 71°F and 72°F in these months. The waters are a bit warmer for the rest of the year, reaching up to 75°F.
If you want to visit this part of Hawaii and enjoy the water, the best time for you to visit would be between August and October, when the ocean is likely to be at its warmest, around 75°F.
Kahului Maui Island
This part of Hawaii has ocean water temperatures a bit higher than the previously mentioned area, with a high of around 80°F and a low reaching 75°F on average. The coldest months of the year, concerning the ocean’s temperature, are between January and April, with temperatures between 75°F and 76°F on average.
The warmest months for this area’s ocean water are August through October, with temperatures around 80°F on average. The rest of the year, excluding the warmest and coldest months, ranges between 77°F and 79°F on average.
Kawaihae Hawaii Island
With the lowest average temperature of this part of Hawaii not going below 77°F, this may be one of the ideal places to spend your time if you are going to Hawaii for the ocean. Between December and April, this area’s ocean water temperature is between 77°F and 78°F, with the rest of the year ranging between 79°F and 81°F.
If you want to plan the best time to go to this part of Hawaii for warmer ocean waters, you should plan to go between June and November, as these are the most likely months to have temperatures in the 80°F range.
Mokuoloe, Oahu Island
This part of Hawaii has waters that range pretty dramatically, with colder months going as low as 73°F and higher months rising to 80°F on average. The coldest months related to the ocean water temperatures are November through to April of the year, and you would likely want to avoid going to this area during this time if you prefer waters above 76°F.
For the rest of the year in this area, the water temperature of the ocean will range from 77°F to 81°F. And the warmest months for swimming or diving are between June and September, with 79°F and 80°F being the likely water temperatures.
Nawiliwili Kauai Island
This area is the part of Hawaii with the warmest ocean waters throughout the year, making it one of the best and most fantastic places to visit if you want to enjoy the warmer waters. The ocean water in this area ranges between 77°F and 83°F, making it the best place to go swimming, diving, or snorkeling year-round.
The times of the year when the ocean waters are the coldest are between December and May, with the average water temperatures ranging between 77°F and 79°F. Throughout the rest of the year, the ocean waters are nearly constantly above 80°F, with the warmest waters being 83°F around September.
The best months to enjoy this area of Hawaii are between July and October, when the water is on average between 82°F and 83°F.

The Best Time Of Year To Visit Hawaiian Beaches
Depending on the area of Hawaii you plan to visit, and depending on whether the temperature of the water is something you are deterred by, there are various times of the year that you may be likely to visit Hawaii.
In general, Hawaii makes a relatively good beach holiday area throughout most of the year if you look at the water’s temperature. However, you may also want to consider the weather and climate during specific times of the year.
If you are planning to go to Hawaii at the times when the ocean water is the warmest, you should probably plan a trip around June through October for the warmest waters. However, it would be best to think about the specific area or areas you want to visit since some areas have better water between July and September instead.
Suppose you are very sensitive to the temperature of the ocean’s water. In that case, it may be best for you to go between July and September since there is a higher chance of the water being a couple of degrees warmer on average.
The Best Areas Of Hawaii To Visit For Warm Water
If you are scheduling a trip to Hawaii and specifically want to go to the areas where the water is the warmest, there are a few places you may consider. Though the temperatures will still range even in the parts of Hawaii with warmer ocean waters, if you choose the right area, the water’s coldest temperatures may equal another area’s warmest water temperatures.
Suppose you are looking for the part of Hawaii with the warmest waters throughout the year. In that case, you will surely wish to go to Nawiliwili Kauai Island since the water temperature rarely dips below the point of 77°F on average, even when the water temperature is low.
In addition to the relatively warm waters during the colder periods, you are likely to have temperatures around 80°F on average between June and October if you visit the Nawiliwili Kauai Island area.
The Areas Of Hawaii To Avoid If You Want Warm Water
If you are willing to go to almost any part of Hawaii but want to avoid the areas with the lowers water temperatures, you may want to avoid going to the Hilo Hawaii Island area. This part of Hawaii has the coldest ocean waters ranging between 71°F and 75°F, even in the warmer times.
The highest ocean water temperature in this part of Hawaii is lower than the average coldest temperature of the Nawiliwili Kauai Island area, which is why you may choose to avoid swimming here.
Conclusion
Though Hawaii has varying ocean water temperatures based on the different areas and times of the year, it gets considered to have relatively warm ocean water. However, it is essential to realize that the warmness of ocean water is hard to gauge since different parts of the world and even the US have different standards of what gets considered warm or cold ocean water.
References:
- https://www.myweather2.com/swimming-and-water-temp-index.aspx
- https://www.ncei.noaa.gov/access/coastal-water-temperature-guide/hawaii.html
- https://web.archive.org/web/20210404022556/https://www.ncei.noaa.gov/access/coastal-water-temperature-guide/hawaii.html
- https://boards.cruisecritic.com/topic/489762-okay-how-cold-really-is-the-water-in-hawaii/
- https://www.surf-forecast.com/breaks/Hawaii/seatemp
- https://www.currentresults.com/Oceans/Temperature/hawaii-average-water-temperature.php
- https://www.govisithawaii.com/2018/10/01/hawaii-ocean-water-temperatures/