Hawaii Island, also known as the Big Island, is known for warm temperatures throughout the year. The entirety of Hawaii Island enjoys a tropical environment with periods of high humidity and rain, but the skies usually sunny.
However, as the largest island in the archipelago, the climate can vary dramatically depending on the area. Island weather, in general, is unpredictable, so it is best to be prepared for sun and rain on any given day. The trade winds that blow almost daily from the northeast condense moisture around the island’s many mountains, making the elevated areas on this side more susceptible to rain. It is important to remember that Hawaii experiences only two seasons, a wet winter season (from November to March) and a dry summer season (from April to October).
Hurricane Season on Hawaii Island
Hurricane season on Hawaii Island runs from the beginning of June to the end of November, typically producing more storms in the months of July and August when the water is warmest. Most people, however, who travel to Hawaii Island during this time are not affected by hurricanes or even bad weather. Even so, you still should be prepared for a hurricane if you're planning to visit from June to November. Since Hawaii Island has the largest surface area and sits at the bottom of the island chain, storms that come from the south or southeast are more likely to cause damage. Visit the Hawaii Department of Health’s hurricane preparedness page for more information on keeping yourself and your family safe.
Lava Flow and Vog (Volcanic Smog) on Hawaii Island
Contrary to what many tourists believe, Hawaii Island is the only island in the state where you’d have to worry about lava flow. The island’s Volcanoes National Park is home to Kīlauea and Mauna Loa, two of the most active volcanoes on Earth. While volcanic smog (vog), the air pollution produced through the gases emitted from an erupting volcano, is present all over the Hawaiian Islands, it will be most prevalent on the Big Island.
Active lava flow may cause the closure of public or private roads, and tour companies will adjust accordingly. Still, the people usually most affected by lava flow are the island’s local residents, who may have to evacuate their homes during a particularly intense bout of eruptions. For example, the extreme volcanic activity that took place beginning in May of 2018 closed Volcanoes National Park for about five months (the longest closure in the history of the 100-year-old park) and added almost 700 acres of new land. Visit the state’s Office of Public Health Preparedness website for any volcano-related advisories or closures.
Vog, may also be a result of volcanic activity on the island, though it depends on the specific area. Those with respiratory issues should visit the Hawaii Interagency Vog Dashboard to get more information and view current and forecasted data on air quality. Additionally, tourists planning a visit to Volcanoes National Park can view specific air quality levels at the National Park Service page.
Different Regions of Hawaii Island
Because of the protection it gets from the Hawaiian wind, this popular area of the island is fairly consistent with dry and warm weather. The leeward Kona area gets so little rain compared to the windward Hilo side that summer precipitation often exceeds winter rainfall.
This windward side of the island experiences the most rain, sometimes between 10 and 40 times as much as Hawaii Island’s driest spots. Thanks to the constant rain, Hilo and the surrounding area have lush, green surroundings that make up for the wet weather.
Volcanoes National Park
The weather in Volcanoes National Park and the neighboring town of Volcano Village has an elevation of 4,000 feet above sea level, making it much cooler than the rest of the island. Wet conditions gives this area a rainforest ambiance despite what most travelers would expect from a volcanic landscape.
High-elevation Waimea (just over 2,500 feet) tends to see cooler temperatures than most other parts of the island. On average, temperature range between the low 60s and the high 70s Fahrenheit (15 to 21 degrees Celsius), though the region often experiences less cloud cover in the evenings than most other spots making it great for stargazing.
Mauna Kea, the highest elevated area in the state of Hawaii, offers a landscape and climate completely unique to the rest of the island. Winter travel to the mountain requires planning, as the summit can often experience blizzard-like climates and temperatures from 17 to 47 degrees Fahrenheit (-8 to 8 degrees Celsius). Even visiting in the summer evenings will require a jacket or sweater at Mauna Kea.
Summer on Hawaii Island
Summer runs from April to October on Hawaii Island, with temperatures slightly higher than the rest of the year. Daily average temperatures range from 85 degrees Fahrenheit to 87 degrees Fahrenheit (29 to 30 degrees Celsius) during the day and can drop as low as 70 degrees Fahrenheit (21 degrees Celsius) at night. The ocean water surface temperature can get into the mid 80s Fahrenheit (27 degrees Celsius) during the summer. Pending occasional rain from storms and hurricanes, this time of year will typically be the driest.
What to pack: Beach clothes such as sandals, shorts and swimsuits are an obvious necessity for summer on the Big Island. The sun this close to the equator is likely much stronger than you’re used to, so sunglasses, hats and reef-friendly sunscreen is a must. There aren’t many (if any) places on the Big Island with a strict dress code, so keep it casual and comfortable.
Winter on Hawaii Island
In the wintertime the temperatures can drop into the mid-60s Fahrenheit (15 degrees Celsius) at night, with an average of 81 to 84 degrees Fahrenheit (27 to 29 degrees Celsius at its warmest. Swimming in the ocean is still very doable in the winter, as the water surface temperature typically doesn’t drop below 77 degrees Fahrenheit (25 degrees Celsius). This time of year often sees the most rain, though keep in mind the localized weather that characterizes Hawaii Island means it may be raining on one side but sunny on the other.
What to pack: You will most likely need a jacket or pants if you’re visiting the areas around Mauna Kea, Volcanoes, or Waimea due to the cooler weather. On all other parts of the island and depending on which activities you choose, a light sweater may come in handy during the evenings. Daytime will require the same clothes as summer, so make sure to pack swimsuits, shorts, T-shirts, and plenty of sun protection for the beach. If you’re staying in Hilo, bring a light raincoat, closed-toed shoes, and an umbrella to combat the rain.
Those traveling to Hawaii Island from November to April will be sharing the waters with some other visitors—humpback whales. These massive and majestic animals call Hawaii home during this time of year, coming to breed and give birth. The Kohala Coast on the north side of the island has some of the highest number of daily sightings during the peak months of January and February, while the Hamakua Coast in the northeast see more in March. Take a whale watching boat tour to see them close-up or, visit one of the many lookouts on the north and northeast shores to see them from land. Puukohola Heiau National Historic Site in North Kohala has some of the best whale-watching views.