Hawaiian Islands are all different. Kauai has one large extinct volcano. Maui has two volcanoes, both barely alive. The Big Island of Hawaii has five volcanoes, four that are still active. O’ahu has two volcanoes, both are extinct. The top of the older volcano, Waianae, is called Mount Ka’ala and stands 4,025 feet above the ocean.
O’ahu is at 21⁰ latitude and receives more sun light than any place on the mainland. This is important because the more overhead light, the less atmosphere it filters through. Thus…wear lots of sunblock and watch your time in the sun.
Cite: O’ahu Revealed by Andrew Doughty