Climate and Average Weather Year Round in Wailua Hawaii, United States

The climate in Wailua is warm, muggy, windy, and partly cloudy. Over the course of the year, the temperature typically varies from 65°F to 86°F and is rarely below 59°F or above 89°F.

Based on the beach/pool score, the best time of year to visit Wailua for hot-weather activities is from late May to late September.

The temperature in Wailua varies so little throughout the year that it is not entirely meaningful to discuss hot and cold seasons.

In Wailua, the average percentage of the sky covered by clouds experiences mild seasonal variation over the course of the year.

The clearer part of the year in Wailua begins around May 13 and lasts for 4.1 months, ending around September 17.

The clearest month of the year in Wailua is August, during which on average the sky is clear, mostly clear, or partly cloudy 76% of the time.

The cloudier part of the year begins around September 17 and lasts for 7.9 months, ending around May 13.

The cloudiest month of the year in Wailua is October, during which on average the sky is overcast or mostly cloudy 41% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Wailua varies throughout the year.

The wetter season lasts 5.3 months, from October 29 to April 8, with a greater than 12% chance of a given day being a wet day. The month with the most wet days in Wailua is January, with an average of 5.7 days with at least 0.04 inches of precipitation.

The drier season lasts 6.7 months, from April 8 to October 29. The month with the fewest wet days in Wailua is June, with an average of 1.4 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in Wailua is January, with an average of 5.7 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 21% on January 11.

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Wailua experiences some seasonal variation in monthly rainfall.

The rainy period of the year lasts for 9.5 months, from August 1 to May 16, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain in Wailua is March, with an average rainfall of 1.5 inches.

The rainless period of the year lasts for 2.5 months, from May 16 to August 1. The month with the least rain in Wailua is June, with an average rainfall of 0.2 inches.

The length of the day in Wailua varies over the course of the year. In 2024, the shortest day is December 20, with 10 hours, 52 minutes of daylight; the longest day is June 20, with 13 hours, 24 minutes of daylight.

The earliest sunrise is at 5:42 AM on June 6, and the latest sunrise is 1 hour, 21 minutes later at 7:03 AM on January 16. The earliest sunset is at 5:42 PM on November 25, and the latest sunset is 1 hour, 28 minutes later at 7:09 PM on July 3.

Daylight saving time (DST) is not observed in Wailua during 2024.

The figure below presents a compact representation of key lunar data for 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

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.

Wailua experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 7.4 months, from May 7 to December 19, during which time the comfort level is muggy, oppressive, or miserable at least 43% of the time. The month with the most muggy days in Wailua is August, with 26.6 days that are muggy or worse.

The month with the fewest muggy days in Wailua is February, with 8.8 days that are muggy or worse.

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 Wailua experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 6.1 months, from March 11 to September 15, with average wind speeds of more than 14.1 miles per hour. The windiest month of the year in Wailua is July, with an average hourly wind speed of 16.2 miles per hour.

The calmer time of year lasts for 5.9 months, from September 15 to March 11. The calmest month of the year in Wailua is January, with an average hourly wind speed of 12.0 miles per hour.

The predominant average hourly wind direction in Wailua is from the east throughout the year.

Wailua 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 water temperature experiences some seasonal variation over the course of the year.

The time of year with warmer water lasts for 3.1 months, from August 1 to November 5, with an average temperature above 79°F. The month of the year in Wailua with the warmest water is September, with an average temperature of 80°F.

The time of year with cooler water lasts for 4.0 months, from January 8 to May 9, with an average temperature below 76°F. The month of the year in Wailua with the coolest water is March, with an average temperature of 75°F.

To characterize how pleasant the weather is in Wailua throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Wailua for general outdoor tourist activities is from late to early October, with a peak score in the second week of June.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Wailua for hot-weather activities is from late May to late September, with a peak score in the first week of August.

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

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 Wailua 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.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences significant seasonal variation over the course of the year.

The brighter period of the year lasts for 4.6 months, from April 16 to September 3, with an average daily incident shortwave energy per square meter above 6.9 kWh. The brightest month of the year in Wailua is June, with an average of 7.5 kWh.

The darker period of the year lasts for 2.9 months, from November 5 to February 1, with an average daily incident shortwave energy per square meter below 5.0 kWh. The darkest month of the year in Wailua is December, with an average of 4.3 kWh.

For the purposes of this report, the geographical coordinates of Wailua are 20.849 deg latitude, -156.136 deg longitude, and 285 ft elevation.

The topography within 2 miles of Wailua contains very significant variations in elevation, with a maximum elevation change of 1,588 feet and an average elevation above sea level of 330 feet. Within 10 miles contains very significant variations in elevation (9,298 feet). Within 50 miles also contains extreme variations in elevation (10,069 feet).

The area within 2 miles of Wailua is covered by water (52%) and trees (39%), within 10 miles by water (47%) and trees (44%), and within 50 miles by water (88%).