October 8, 2011

General Weather Patterns of Hawai’i


The best thing about Hawai’i's weather is that it is very localized. You may be driving along the island and be in a rain storm one minute and in bright sun the next. This variety of weather allows you to fully experience Hawai’i and its sun-drenched beaches, misty rainbow-filled valleys, pristine waterfalls, cool highlands, and lush mountains. The chart seen to the right here shows the distribution of precipitation annually on the islands; click the chart to enlarge it.

Hawaii, like all the other major Hawaiian islands, is affected by the trade winds. These winds blow NE to ENE and are typically more prevalent in the winter months. These trade winds bring cool air to the islands from the north, often resulting in precipitation along mauka and windward areas. At times, these winds can die down and practically reverse so that a south wind blows over the islands, resulting in very hot and muggy conditions. These winds are called Kona winds.

One mistake a lot of people make when they visit Hawai’i is assuming there is a wet and/or dry season like back home, but it’s not quite that simple. Granted, there are two distinct times of year and weather patterns due to the trade winds, but there is no defined “rainy season.” The general point to be made is, you can’t just say it’s rainy in the winter and dry in the summer. We’ve seen it bone dry in the winter, and had flooding in the summer; each enough times to derail most short-term trends. Still, we can look at the long term trends and get a general idea of what to expect. Let’s take a look.