Hurricane Olivia was a Category 4 hurricane that hit Hawaii as a weakening tropical storm in September 2018, causing severe flooding and wind damage. Olivia was the first tropical cyclone to make landfall on either Maui or Lanai since modern weather records began. It was the fifteenth named storm, ninth hurricane, and sixth major hurricane of the 2018 Pacific hurricane season. A tropical depression formed southwest of Mexico on September 1 and strengthened into a tropical storm a day later. Olivia peaked as a Category 4 hurricane on September 7, with winds of 130 mph (210 km/h) and a minimum pressure of 951 mbar (28.08 inHg). On September 12 the storm weakened and made brief landfalls on Maui and Lanai, with winds of 45 mph (70 km/h). Torrential rainfall occurred on both Maui and Oahu, peaking at 12.93 in (328 mm) in West Wailuaiki, Maui. Olivia felled trees on Maui, and some homes and vehicles were swept away by floodwaters. (This article is part of a featured topic: 2018 Pacific hurricane season.)