Average Weather at Kahului Airport Hawaii, United States
The climate at Kahului Airport is warm, muggy, windy, and mostly clear. Over the course of the year, the temperature typically varies from 65°F to 88°F and is rarely below 58°F or above 90°F.
Based on the beach/pool score, the best time of year to visit Kahului Airport for hot-weather activities is from late May to late September.
The temperature at Kahului Airport varies so little throughout the year that it is not entirely meaningful to discuss hot and cold seasons.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
At Kahului Airport, 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 at Kahului Airport begins around December 8 and lasts for 4.3 months, ending around April 18. On January 18, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 78% of the time, and overcast or mostly cloudy 22% of the time.
The cloudier part of the year begins around April 18 and lasts for 7.7 months, ending around December 8. On October 31, the cloudiest day of the year, the sky is overcast or mostly cloudy 42% of the time, and clear, mostly clear, or partly cloudy 58% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at Kahului Airport varies throughout the year.
The wetter season lasts 6.4 months, from October 12 to April 23, with a greater than 14% chance of a given day being a wet day. The chance of a wet day peaks at 22% on January 14.
The drier season lasts 5.6 months, from April 23 to October 12. The smallest chance of a wet day is 7% on June 18.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 22% on January 14.
Daily Chance of Precipitation
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. Kahului Airport experiences some seasonal variation in monthly rainfall.
The rainy period of the year lasts for 10 months, from July 15 to May 25, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around January 2, with an average total accumulation of 1.9 inches.
The rainless period of the year lasts for 1.7 months, from May 25 to July 15. The least rain falls around June 14, with an average total accumulation of 0.3 inches.
Average Monthly Rainfall
The length of the day at Kahului Airport varies over the course of the year. In 2018, the shortest day is December 21, with 10 hours, 52 minutes of daylight; the longest day is June 21, with 13 hours, 24 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:43 AM on June 7, and the latest sunrise is 1 hour, 21 minutes later at 7:05 AM on January 16. The earliest sunset is at 5:43 PM on November 26, and the latest sunset is 1 hour, 28 minutes later at 7:11 PM on July 4.
Daylight saving time (DST) is not observed at Kahului Airport during 2018.
Sunrise & Sunset with Twilight
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.
Kahului Airport experiences extreme seasonal variation in the perceived humidity.
The muggier period of the year lasts for 7.2 months, from May 12 to December 18, during which time the comfort level is muggy, oppressive, or miserable at least 41% of the time. The muggiest day of the year is August 17, with muggy conditions 83% of the time.
The least muggy day of the year is February 18, with muggy conditions 27% of the time.
Humidity Comfort Levels
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 at Kahului Airport experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 3.7 months, from May 21 to September 12, with average wind speeds of more than 13.8 miles per hour. The windiest day of the year is June 26, with an average hourly wind speed of 16.0 miles per hour.
The calmer time of year lasts for 8.3 months, from September 12 to May 21. The calmest day of the year is January 23, with an average hourly wind speed of 11.6 miles per hour.
Average Wind Speed
The predominant average hourly wind direction at Kahului Airport is from the east throughout the year.
Kahului Airport 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 2 to November 6, with an average temperature above 79°F. The day of the year with the warmest water is September 18, with an average temperature of 80°F.
The time of year with cooler water lasts for 4.0 months, from January 8 to May 8, with an average temperature below 76°F. The day of the year with the coolest water is February 18, with an average temperature of 75°F.
Average Water Temperature
Best Time of Year to Visit
To characterize how pleasant the weather is at Kahului Airport 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 Kahului Airport for general outdoor tourist activities is from early November to late September, with a peak score in the second week of February.
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 Kahului Airport for hot-weather activities is from late May to late September, with a peak score in the first week of August.
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 at Kahului Airport 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.
Time Spent in Various Temperature Bands and the Growing Season
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.
Growing Degree Days
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 15 to September 4, with an average daily incident shortwave energy per square meter above 6.9 kWh. The brightest day of the year is June 9, with an average of 7.6 kWh.
The darker period of the year lasts for 2.8 months, from November 6 to February 1, with an average daily incident shortwave energy per square meter below 5.0 kWh. The darkest day of the year is December 20, with an average of 4.3 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Kahului Airport are 20.899 deg latitude, -156.430 deg longitude, and 16 ft elevation.
The topography within 2 miles of Kahului Airport contains only modest variations in elevation, with a maximum elevation change of 230 feet and an average elevation above sea level of 36 feet. Within 10 miles contains only modest variations in elevation (5,689 feet). Within 50 miles also contains extreme variations in elevation (10,069 feet).
The area within 2 miles of Kahului Airport is covered by cropland (42%), water (37%), and artificial surfaces (16%), within 10 miles by water (38%) and cropland (25%), and within 50 miles by water (86%).
This report illustrates the typical weather at Kahului Airport, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
Kahului Airport has a weather station that reported reliably enough during the analysis period that we have included it in our network. When available, historical temperature and dew point measurements are taken directly from this weather station. These records are obtained from NOAA's Integrated Surface Hourly data set, falling back on ICAO METAR records as required.
In the case of missing or erroneous measurements from this station, we fall back on records from nearby stations, adjusted according to typical seasonal and diurnal intra-station differences. For a given day of the year and hour of the day, the fallback station is selected to minimize the prediction error over the years for which there are measurements for both stations.
The stations on which we may fall back are Lanai Airport, Molokai Airport, Kona International Airport, Bradshaw Army Airfield, Marine Corps Air Station Kaneohe Bay, Honolulu International Airport, and Hilo International Airport.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.
The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.
We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.
We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.