A series of rotating air cells circulates air from the warmer areas near the equator toward the poles and then back again. (Those air cells swirl around the globe at the same band of latitude both above and below the equator, missing the continental U.S. altogether.) The warm air rises to the south of the Hawaiian islands and moves — at high levels — northward. It drops back to sea level north of Hawaii and flows again toward the equator. That crates winds that blow along the surface of the ocean from the northeast. Those are what we call the trade winds. They got their name from the early traders who sailed all over the world, became familiar with the winds and used them well for navigation and speed.

When there are no trade winds in Hawaii, we get Kona winds, which bring the vog (volcanic fog) from the Big Island to the other islands, especially Maui and Oahu. “Kona” is Polynesian word for “leeward.” Kona winds come from the opposite direction of the trades — from the south- and west-facing leeward sides. They can be h3 and gusty, and bring warm and muggy conditions to Hawaii.”

https://www.hawaii-aloha.com/blog/2008/06/05/about-hawaiis-trade-winds/