Big Island Snorkling Tours Blog

Summer Weather in Kailua-Kona Hawaii, United States

Weather Spark on summer weather in Kailua Kona.  Anytime of the year is the best time to join us on a snorkel or manta ray tour!

Daily high temperatures are around 86°F, rarely falling below 82°F or exceeding 89°F. The highest daily average high temperature is 87°F on August 21.

Daily low temperatures are around 74°F, rarely falling below 71°F or exceeding 78°F. The highest daily average low temperature is 76°F on August 9.

For reference, on August 21, the hottest day of the year, temperatures in Kailua-Kona typically range from 75°F to 87°F, while on January 20, the coldest day of the year, they range from 68°F to 81°F.


The summer in Kailua-Kona experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 35% throughout the season. The lowest chance of overcast or mostly cloudy conditions is 31% on August 8.

The clearest day of the summer is August 8, with clearmostly clear, or partly cloudy conditions 69% of the time.

For reference, on October 15, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 52%, while on January 18, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 74%.


wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Kailua-Kona, the chance of a wet day over the course of the summer is essentially constant, remaining around 18% throughout.

For reference, the year’s highest daily chance of a wet day is 31% on March 15, and its lowest chance is 16% on September 10.


To show variation within the season and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day.

The average sliding 31-day rainfall during the summer in Kailua-Kona is rapidly increasing, starting the season at 1.0 inches, when it rarely exceeds 2.5 inches, and ending the season at 2.3 inches, when it rarely exceeds 4.7 inches.

The lowest average 31-day accumulation is 0.9 inches on June 6.


Over the course of the summer in Kailua-Kona, the length of the day is decreasing. From the start to the end of the season, the length of the day decreases by 44 minutes, implying an average daily decrease of 29 seconds, and weekly decrease of 3 minutes, 21 seconds.

The shortest day of the summer is August 31, with 12 hours, 31 minutes of daylight and the longest day is June 21, with 13 hours, 19 minutes of daylight.

The earliest sunrise of the summer in Kailua-Kona is 5:44 AM on June 5 and the latest sunrise is 24 minutes later at 6:08 AM on August 31.

The latest sunset is 7:06 PM on July 5 and the earliest sunset is 27 minutes earlier at 6:39 PM on August 31.

Daylight saving time is not observed in Kailua-Kona during 2022.

For reference, on June 21, the longest day of the year, the Sun rises at 5:46 AM and sets 13 hours, 19 minutes later, at 7:05 PM, while on December 21, the shortest day of the year, it rises at 6:53 AM and sets 10 hours, 57 minutes later, at 5:50 pm.


We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The chance that a given day will be muggy in Kailua-Kona is rapidly increasing during the summer, rising from 71% to 83% over the course of the season.

The highest chance of a muggy day during the summer is 86% on August 8.

For reference, on August 2, the muggiest day of the year, there are muggy conditions 86% of the time, while on February 18, the least muggy day of the year, there are muggy conditions 27% of the time.


This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Kailua-Kona is essentially constant during the summer, remaining within 0.1 miles per hour of 4.5 miles per hour throughout.

For reference, on December 5, the windiest day of the year, the daily average wind speed is 6.9 miles per hour, while on September 18, the calmest day of the year, the daily average wind speed is 4.2 miles per hour.

Water Temperature

Kailua-Kona is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average surface water temperature in Kailua-Kona is gradually increasing during the summer, rising by 2°F, from 78°F to 80°F, over the course of the season.

Growing Season

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

Temperatures in Kailua-Kona are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

The average accumulated growing degree days in Kailua-Kona are very rapidly increasing during the summer, increasing by 2,754°F, from 3,942°F to 6,696°F, over the course of the season.


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