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The Best Time of Year for the Water Temperature in Kona Hawaii

map of the pacific ocean with water temperature heat map

Guide to Water Temperature in Kona Hawaii

Looking for warm waters? Just Imagine lounging on an inflatable raft sipping Mai Tais in the sun or snorkeling inches above multicolor reefs in just a bikini. These are some of the possibilities when you come to visit the Big Island of Hawaii. But sometimes the ocean can be downright chilly here. In this guide to water temperature in Kona Hawaii we’ll go over the temperatures experienced here and how they can vary based on time of year and location among other factors.


a fish swimming under water


The Average Sea Surface Temperature on the western side of Hawaii Island is about 80 °F or 26.7 °C.


In This guide We Cover

What is Warm Water?

Kona Water Temperature By:

Time of Year



Time of Day

How does Kona water Temperature compare to Hilo?



What is warm water?

Many people envision white sand (or black sand beaches) with palm trees and warm tropical waters when they invision Hawaii. While the water temperature in Kona Hawaii is typically much warmer than waters off of the Mainland United States some people still get cold while snorkeling on the Big Island. and some may be surprised or even shocked by the temperature when they first get in.

As you get closer to the equator the water gets warmer. Kona is located 19.6 degrees above the equator which is considered tropical but it’s not as close to the equator as other tropical islands.

Water has a high heat capacity. This means it takes a lot to warm it up unlike air. This means that it will draw a lot of heat away from your body. You can get hypothermia sitting in water as warm as 90 °F if you sit in it long enough. The water in Hawaii to some people can be chilly with people often getting cold during a manta ray night snorkel or Deluxe am Kona Snorkeling Tour. That’s why we usually provide wetsuits to everyone.

Everybody is different and there are a few factors that affect whether you will get cold. One of the biggest (no pun intended) factors that affects your body’s ability to stay warm in the water is the amount of bioprene (body fat) a person has. The more bioprene we have the less likely we will be to get cold in the water. If you look at an animal like a seal you will see what we mean!


Kona Water Temperature by Time of Year

In the tropics the water is typically not subject to large variations day to day. This is what allows coral to form and remain. Large swings in temperature can stress the coral. Because of the relatively small swings in temperature coral can exist in Hawaii. Surface water temperature typically varies by 1-2 degrees per day. From one day to the next water temperatures can change as much as 3.1 degrees or as little as 0.1 degree.

Being that Hawaii is close to the equator it also receives a similar amount of sun throughout the year. The shortest days in the winter are about 11 hours while the longest days in the summer are 13.5 hours. Because the sun is shining similarly throughout the year the temperatures in the coldest winter months are not grossly different than sea surface temperatures in the hottest summer months. This means a small variation in both air and water temperatures compared to many places in the United States for example.Compared to California the water temperature in Kona Hawaii hardly changes!


Kona Water Temperature by Location

The temperature of the ocean is not the same everywhere. On a larger scale this is because the spin of the earth creates currents that can carry warm and cold waters to different places before they mix together to make one temperature.

On a Smaller scale at places like beach parks and bays you will find the water can be quite chilly especially when you just get in. Places like Kailua Bay or Two Step have a nearly constant flow of fresh water coming off shore. This fresh water comes from the island. When it rains up on Hualalai or any other mountain top the water then filters down below the island and seeps out near the shoreline. The freshwater is less dense than the ocean water and so it will create visual distortions and make it difficult to see underwater at times. This is caused by the difference in light refraction of the water because of its differing density.

It is often the case that coastal water is warmer in shallow lagoons where there isn’t much flow and the sun has an opportunity to heat the water up. This is common in places like Kukio where the lagoon restricts surface water movement. You may also feel the cold fresh water coming up through the sand in the same lagoon area.


Kona Water Temperature by Depth

The temperature of the ocean in Kona is fairly constant. The surface water will mostly be affected in bays by sun warming or cold water fresh water runoff. Coastal waters will be a mostly uniform temperature until great depths are reached. Typically this is around 600 feet (200 meters) below the surface. The deep seawater that gets pulled up at the Natural Energy Laboratoy is 4°C and comes from 3000 feet (1000 meters) deep.


Kona Water Temperature by Time of Day

The water temperature in Kona Hawaii will typically vary by 1-2 degrees from day to night. This fluctuation can be less and is difficult to perceive.


How does Kona Water Temperature Compare to Hilo?

The ocean surface water is typically warmer in Kona than in Hilo by 5-6 degrees Fahrenheit.


table of water temperatures in Hawaii locations by month




How does the water temperature compare in Hawaii versus other Places?

Hawaii Island is located in the northern tropics. This means it’s not as close to the equator as other locations like the Caribbean or other well known tourism hotspots. This is not necessarily bad it just means the Water temperature in Kona Hawaii is typically a bit cooler than say Jamaica.

Where did you Get your Information From?

We used temperature monitoring data from NOAA’s station located in Kawaehae. While this is north of Kona it is one of the most reliable data sources. Click here to see it for yourself.


Now it’s time for a snorkel!

Now that you know how warm the water temperature in Kona Hawaii is you want to go snorkeling so check out our Top 15 Spots for the Best Snorkeling on Big Island.