When to make a break for the Big Island
With 11 of the world's 13 possible climates on the Big Island, you might think that the best time to visit would be up for grabs. But ... not really. It's pretty much warm and mostly sunny year-round, assuming that your vacation plans emphasize the beach and the ocean. If instead, you are going to hike Mauna Loa or stargaze at Mauna Kea, or you're planning a lengthy trip that includes upland areas like Waimea, you will want to plan your trip more carefully. But to avoid crowds and accompanying high prices, it's best to go in spring or fall.
Most people agree that April through June and September through November are the best overall times to visit the Big Island, not only to avoid the prices and crowds, but to ensure the best weather.
Sun, Rain and Temps
The Big Island's weather varies widely from spot to spot on any given day, but overall coastal temperatures are pretty constant with highs in the upper 80s in summer and lower 80s in the winter. But several factors you might not think about can drastically impact the weather, and therefore your vacation experience. Read on.
Windward or Leeward: The Big Island has a leeward (west and south) and a windward (east and north) side. The difference in weather, especially rainfall, is dramatic. Kona on the west is dry, averaging from 20 to 60 inches of rain per year, depending on location. The Hilo side, however, averages 200 to 300 inches of rain a year!
Wet Season or Dry Season: For most of the island, the wet season is winter from November to March, and the dry season is summer from June through September, but the island does have some microclimates. For example, the mountain coffee lands south of Kailua-Kona from around Kealekekua to Honaunau can experience more rain in the summer months. Generally, even if it does rain, sun is right around the corner or just a few miles away, and there's almost always a rainbow to enjoy unless there is a storm or even a hurricane brewing, which is rare. Hurricane season is from June to November.
Mauka or makai: Most visitors to Hawaii remain makai – at sea level near the beaches and resorts or in the lower elevations where the temps stay warm and there is less rainfall. If you do go mauka – up into the mountains or on the mountain side of the Hawaii Belt Road, the main highway circling the island – you'll experience cooler temps and more rainfall. This is true of Waimea, the village of Volcano including the Volcanoes National Park, and the Saddle Road, which takes you from the Kona side to the Hilo side of the island through the mountain passes between the peaks of Mauna Kea and Mauna Loa.
Consider the crowds
Like all the Hawaiian islands, the Big Island attracts the most tourists during summer and winter, especially over the holidays. In winter, visitors are fleeing the weather in more northern climes, while summer attracts families whose kids are out of school. These are the most crowded and the most expensive times to visit, lodging-wise. Also, Japan's Golden Week sends large numbers of Japanese tourists to the Big Island as that country celebrates four national holidays during the last week of April and the first week of May.
Traffic in Paradise
Yes, the Big Island admits to some traffic nightmares, due to the single road that circles the island, the Hawaii Belt Road. Rush hour clogs this mostly single lane highway, especially anywhere near Kailua-Kona and Waimea. Many residents work in town and live in the rural or suburban areas, so traffic follows the same pattern as in most places: avoid mornings heading into town and evenings heading out of town.
The Vulcan side
Hawaii's famously active volcanoes lend a mesmerizing aspect to a Big Island trek. Where else can you peer into a smoking caldera or tiptoe within feet of a hissing lava flow and live to tell the tale back home? Kilauea's ongoing eruption – since 1983 – has engulfed entire villages and created more than 500 acres of new land. There is, however, no special season or weather for observing the volcano: lava waits for no man. But Kilauea's glowing lava lake is especially dramatic after sunset, so be prepared for crowds between 5:30 p.m. and 7:30 p.m.