Maui enjoys a wonderful tropical climate with year-round warmth moderated by the vast Pacific that surrounds the Hawaiian Islands. It’s hard to go wrong here in terms of the weather, especially compared with most of mainland North America. Even considered against many other tropical locales, Maui (and the rest of Hawaii) are appealing given the quite low incidence of hurricanes here.
That said, there are some interesting (if comparatively modest) seasonal differences in Maui’s weather. Let’s dig into those so you can figure out the best time to come to the glorious Valley Isle!
Basic Sketch of Maui’s Weather
The major influence on Maui’s weather (and that of the rest of the Hawaiian Islands) is the northeasterly airflow of the trade winds. These breezes stem from a major area of high pressure known as the Pacific High (or Pacific Anticyclone).
OK, here’s an extremely simplified explanation of the general effect of those trade winds on Maui’s weather. It involves a little Atmospheric Science 101—but only a little, we promise! Air forced upward cools down, and cooler air can’t hold as much moisture. So in an air mass that’s shoved up in altitude, water vapor will condense into clouds and, possibly, into precipitation. Over the open ocean around Maui, the trade winds aren’t generally forced upward by anything to produce much in the way of clouds and rainfall. Indeed, precipitation out to sea around these parts is only about 20 or 25 inches per year.
Maui, though, comes dominated by some significant topographic relief in the form of the West Maui Mountains in the west and Haleakala in the east. When the trade winds hit the slopes of these highlands, they generate clouds and rain showers. Precipitation tends to increase with elevation up to a certain point on Maui. A soggy montane rainforest site called Big Bog, up at about 5,400 feet on the northeastern flank of Haleakala receives more than 400 inches of rain on average each year! That puts it right up there as possibly the wettest spot in Hawaii, though Kauai’s Mount Waialeale is a rival for that crown.
The windward slopes of Maui are cloudier, rainier, and cooler. The leeward (aka southerly and southwesterly) slopes are clearer, drier, and warmer. That’s because the trade winds are sort of “wrung out” by their passage over the mountains, and because descending air warms up (and thus can hold more moisture without condensing clouds).
East Maui includes the highest point on the island: the magnificent 10,023-foot crown of Haleakala. That’s a lofty-enough elevation to rise above the commonplace trade-wind inversion layer present over the Hawaiian Islands. Up between about 6,000 and 8,000 feet, warm air embedded in the trade winds overlies cooler air, forming a meteorological inversion. This puts a cap on rising air masses and thus the formation of clouds. So clear weather, especially in the first half of the day, often prevails around Haleakala above a windward cloud deck. The great Koolau Gap, a breach on the northern rim of the Haleakala “Crater,” often allows the lower stratus clouds to penetrate the otherwise-sunny summit region.
The West Maui Mountains top out below 6,000 feet—in other words, below the inversion layer—and thus tend to be pretty cloudy in their high country, though mornings are clearer.
Trade-wind weather, with its windward cloudiness and leeward sunniness, is most prevalent on Maui in the summer. That’s because the Pacific High, that high-pressure zone creating the trades, is the strongest and farthest north during this season. The Pacific High follows the sun, you see, and in winter, as the sun moves south, so does the high-pressure cell. It also weakens in the wintertime. So winter on Maui, while still generally dominated by trade-wind conditions, sees more frequent interruptions of that weather. Kona storms and other major disturbances impact the island more regularly and bring more torrential and widespread rainfall than the comparatively light trade-wind precipitation of windward Maui.
This makes for, very roughly, a summer “dry season” (while still plenty cloudy and showery on the windward side) and a winter “wet season” on the Valley Isle. Considered island-wide, the summer months are somewhat drier, the winter months—with occasional storm-driven downpours that bring precipitation to leeward as well as windward sides of the island—wetter.
Maui’s Regional Sub-climates
That simplified description of Maui’s yearly climate will help you understand the sub-climates found on the island, which can influence your vacation. Windward Maui is lusher, wetter, and cloudier, which makes for luxuriant rainforest vegetation and stunning waterfalls. Driving the Road to Hana shows off that well-watered lushness. But the main resort hubs, such as Lahaina and Kihei, are situated in leeward Maui, given the drier, sunnier prevailing weather.
The Haleakala alpine zone, up in the vicinity of 10,000 feet, is understandably colder than the rest of Maui. Expect daily highs in the 50s up top. That means bundling up if you want to take in the famous sunrise from the crown of the island.
The Central Valley of Maui, which is the isthmus between the West Maui Mountains and Haleakala Volcano, is its own sub-climate. The northern, or “windward,” part of the Valley is a bit wetter, and the leeward side drier. But overall, given its low elevation, it’s a drier zone compared with the two mountainous realms that flank it.
Monthly Weather Guide
Generally speaking, you’ll enjoy temperatures on Maui in the 70s or 80s degrees Fahrenheit. The winter rainy season is slightly cooler than the summer dry season, but the temperature difference—as is typical in the tropics—is negligible.
We’ll present average annual high and low temperatures (in degrees F) and average rainfall for two locations on Maui: Lahaina Airport, which is fairly representative of the coastal tourist zones of leeward Maui, and Hana, a popular windward destination.
Lahaina Month-by-Month Weather
January
High: 81
Low: 63
Rainfall: 2.87”
February
High: 81
Low: 63
Rainfall: 1.96”
March
High: 81
Low: 64
Rainfall: 2.45”
April
High: 82
Low: 66
Rainfall: 1.55”
May
High: 84
Low: 67
Rainfall: 0.74”
June
High: 86
Low: 70
Rainfall: 0.20”
July
High: 87
Low: 71
Rainfall: 0.50”
August
High: 88
Low: 72
Rainfall: 0.50”
September
High: 88
Low: 70
Rainfall: 0.38”
October
High: 87
Low: 70
Rainfall: 1.20”
November
High: 84
Low: 68
Rainfall: 2.20”
December
High: 82
Low: 65
Rainfall: 3.35”
Hana Month-by-Month Weather
January
High: 78
Low: 65
Rainfall: 5.5”
February
High: 78
Low: 64
Rainfall: 4.6”
March
High: 78
Low: 65
Rainfall: 7.3”
April
High: 78
Low: 67
Rainfall: 5.2”
May
High: 80
Low: 68
Rainfall: 3.5”
June
High: 82
Low: 70
Rainfall: 2.8”
July
High: 82
Low: 71
Rainfall: 3.9”
August
High: 83
Low: 72
Rainfall: 3.8”
September
High: 83
Low: 70
Rainfall: 3”
October
High: 82
Low: 70
Rainfall: 4”
November
High: 80
Low: 69
Rainfall: 5.4”
December
High: 79
Low: 67
Rainfall: 6.7”
Best Time to Visit Maui
The peak tourism windows in Maui are winter when folks from the mainland are fleeing the cold, and summer, which coincides with school vacations. These aren’t exactly the nicest periods weather-wise, given the winter storm season and the higher temperatures of summer. There isn’t really a true “spring” and “fall” on Maui, but the April-to-May and September-to-November stretches are transitional periods that generally offer really nice weather. They also tend to translate to lower rates and crowds.
That said, Maui weather any time of year is pretty delightful compared to most parts of the world. You can count on warm weather year-round except up on the Haleakala summit. The trade-wind showers of windward Maui tend to be fleeting, and actually often occur overnight, so all things considered they shouldn’t spoil your day. And winter storms on the island are only periodic, and at most their heavier rains and blusteriness last just a few days.
We’ll close, though, by noting that if you’re coming to Maui for its absolutely world-class surfing, winter—with its big northerly swells—is prime time for you!
