What are the Wettest and Driest Parts of the Big Island? The western (leeward) side of the Big Island, including Kailua-Kona and Waikoloa, tends to be drier, with annual rainfall often below 30 inches. The eastern (windward) side, including Hilo and Puna, is much wetter, with annual rainfall often exceeding 100 inches. The wettest locations […]