Which Island of Hawaii gets the most thunderstorms?
This isn’t the answer you are looking for. While storms are frequent thunder and lightning is rare. So rare in fact that the site in the link says “Indeed, a flash of lightening followed by a crash of thunder is infrequent enough so that many people who have lived only in Hawaii have no real notion of the violence of Mainland thunderstorms as evidenced by the lightning and thunder that are their typical accompaniment.” For what it’s worth the variations in storm frequency occur not so much between the islands as according to the windward or leeward exposure of regions on the islands. The leeward lowlands experience the most intense storms. The islands are also influenced by major storm systems, usually occurring between October and March. Sources: http://www.wrcc.dri.edu/narratives/HAWAII.