May Weather in Lahaina Hawaii, United StatesDaily high temperatures increase by 2°F, from 83°F to 85°F, rarely falling below 80°F or exceeding 88°F. Daily low temperatures increase by 2°F, from 68°F to 70°F, rarely falling below 65°F or exceeding 73°F. For reference, on August 26, the hottest day of the year, temperatures in Lahaina typically range from 73°F to 87°F, while on January 28, the coldest day of the year, they range from 65°F to 81°F. The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on May. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day. Villalba, Puerto Rico (5,796 miles away) is the far-away foreign place with temperatures most similar to Lahaina (view comparison). CloudsThe month of May in Lahaina experiences gradually decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 32% to 27%. The clearest day of the month is May 31, with clear, mostly clear, or partly cloudy conditions 73% of the time. For reference, on October 30, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 42%, while on January 18, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 78%. PrecipitationA wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Lahaina, the chance of a wet day over the course of May is rapidly decreasing, starting the month at 15% and ending it at 9%. For reference, the year's highest daily chance of a wet day is 23% on January 11, and its lowest chance is 9% on June 19. RainfallTo show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day. The average sliding 31-day rainfall during May in Lahaina is decreasing, starting the month at 1.3 inches, when it rarely exceeds 2.9 inches, and ending the month at 0.5 inches, when it rarely exceeds 1.2 inches. SunOver the course of May in Lahaina, the length of the day is gradually increasing. From the start to the end of the month, the length of the day increases by 23 minutes, implying an average daily increase of 47 seconds, and weekly increase of 5 minutes, 27 seconds. The shortest day of the month is May 1, with 12 hours, 56 minutes of daylight and the longest day is May 31, with 13 hours, 19 minutes of daylight. The latest sunrise of the month in Lahaina is 5:55 AM on May 1 and the earliest sunrise is 11 minutes earlier at 5:45 AM on May 31. The earliest sunset is 6:51 PM on May 1 and the latest sunset is 12 minutes later at 7:04 PM on May 31. Daylight saving time is not observed in Lahaina during 2024. For reference, on June 20, the longest day of the year, the Sun rises at 5:46 AM and sets 13 hours, 24 minutes later, at 7:10 PM, while on December 21, the shortest day of the year, it rises at 6:59 AM and sets 10 hours, 52 minutes later, at 5:51 PM. The figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation. MoonThe figure below presents a compact representation of key lunar data for May 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. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.
HumidityWe 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 Lahaina is very rapidly increasing during May, rising from 35% to 56% over the course of the month. For reference, on August 16, the muggiest day of the year, there are muggy conditions 85% of the time, while on March 5, the least muggy day of the year, there are muggy conditions 27% of the time. WindThis 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 Lahaina is essentially constant during May, remaining within 0.4 miles per hour of 13.5 miles per hour throughout. For reference, on July 2, the windiest day of the year, the daily average wind speed is 15.5 miles per hour, while on January 10, the calmest day of the year, the daily average wind speed is 11.4 miles per hour. The lowest daily average wind speed during May is 13.1 miles per hour on May 18. The hourly average wind direction in Lahaina throughout May is predominantly from the east, with a peak proportion of 92% on May 31. Water TemperatureLahaina 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 Lahaina is essentially constant during May, remaining within 1°F of 77°F throughout. Growing SeasonDefinitions 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 Lahaina 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 Lahaina are rapidly increasing during May, increasing by 781°F, from 2,770°F to 3,551°F, over the course of the month. Solar EnergyThis 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 in Lahaina is essentially constant during May, remaining within 0.2 kWh of 7.4 kWh throughout. TopographyFor the purposes of this report, the geographical coordinates of Lahaina are 20.874 deg latitude, -156.677 deg longitude, and 36 ft elevation. The topography within 2 miles of Lahaina contains very significant variations in elevation, with a maximum elevation change of 1,076 feet and an average elevation above sea level of 141 feet. Within 10 miles contains very significant variations in elevation (5,771 feet). Within 50 miles also contains extreme variations in elevation (10,069 feet). The area within 2 miles of Lahaina is covered by water (45%), shrubs (22%), artificial surfaces (15%), and grassland (12%), within 10 miles by water (61%) and trees (18%), and within 50 miles by water (85%). Data SourcesThis report illustrates the typical weather in Lahaina, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016. Temperature and Dew PointThere are 2 weather stations near enough to contribute to our estimation of the temperature and dew point in Lahaina. For each station, the records are corrected for the elevation difference between that station and Lahaina according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations. The estimated value at Lahaina is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Lahaina and a given station. The stations contributing to this reconstruction are:
To get a sense of how much these sources agree with each other, you can view a comparison of Lahaina and the stations that contribute to our estimates of its temperature history and climate. Please note that each source's contribution is adjusted for elevation and the relative change present in the MERRA-2 data. Other DataAll data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , 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 airports and weather stations are provided by AskGeo.com . Maps are © OpenStreetMap contributors. DisclaimerThe 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. Please review our full terms contained on our Terms of Service page. |