Hurricane Lane was a powerful tropical cyclone that brought torrential rainfall and strong winds to Hawaii during late August 2018.

The storm was the wettest on record in Hawaii, with peak rainfall accumulations of 58 inches (1,473 mm) along the eastern slopes of Mauna Kea.

Temporarily inhibited by more hostile conditions, the hurricane weakened slightly before regaining strength and reaching Category 5 status on August 22 to the south of Hawaii.

From August 22 to 26, Lane brought heavy rain to much of the Hawaiian Windward Islands, which caused flash flooding and mudslides.

[nb 2] On September 27, 2018, President Donald Trump declared much of Hawaii a disaster area; the Federal Emergency Management Agency ultimately provided about $10 million in aid.

It moved west across the Atlantic with little to no convection (shower and thunderstorm activity) before crossing Central America and entering the Eastern Pacific basin on August 8.

[1][3] A large subtropical ridge to the north steered the nascent system on a general west to west-northwest course, a direction it would maintain for about a week.

[1][5] Favorable environmental conditions, including warm sea surface temperatures averaging 81.5–82.4 °F (27.5–28 °C) and low wind shear, fostered intensification.

[1] A defined inner-core with symmetrical outflow aloft organized by August 17, and microwave satellite imagery showed an eye at the lower levels of the cyclone.

[8][9] Around 12:00 UTC that day, Lane reached its initial peak intensity with winds of 140 mph (225 km/h), approximately 1,810 mi (2,915 km) southwest of Baja California Sur.

[1] Early on August 19, the Central Pacific Hurricane Center (CPHC)[nb 4] assumed responsibility of the storm after it crossed 140°W.

[1][19] The circulation center became exposed with meager convection restricted to the northeast early on August 25, marking Lane's degradation to a tropical storm.

[1] All school districts statewide closed between August 22 and 24, and all non-essential state employees on the Big Island and Maui were told to stay home on those days.

[34] On August 22, the United States Navy and Air Force repositioned assets statewide, primarily at the Joint Base Pearl Harbor–Hickam, to protect them from the hurricane.

Navy vessels not undergoing maintenance were ordered to sortie, though remain in close enough proximity for quick relief efforts if needed.

The Department of Homeland Security's Federal Emergency Management Agency (FEMA) was authorized to coordinate disaster relief beginning on August 22 and continuing indefinitely.

[44][45] This made Lane the wettest tropical cyclone on record in the state of Hawaii, surpassing the previous peak of 52 in (1,300 mm) during Hurricane Hiki in 1950.

[45] Lane's peak rainfall total was also the second-highest recorded from a tropical cyclone within the United States, surpassed only by Hurricane Harvey in the preceding year.

[45] Precipitation in the Hilo Region was likely amplified by the terrain on the windward side of the island, the position of rainbands, the environment generated by the cyclone, and katabatic winds.

As Lane approached on August 23, enhanced flow associated with it and a ridge to the north produced strong, dry winds in western Maui.

[60] Fires sparked in areas with dry brush and grew rapidly, fanned by wind gusts estimated at 60–80 mph (97–129 km/h).

[63] Around a dozen agricultural businesses and farmers suffered hundreds of thousands of dollars in losses from the fires, with some losing large portions of their crop and equipment.

[69] Rivers and streams swelled due to heavy rains, especially in the Wainiha and Hanalei Valleys;[69] waters submerged roads and taro patches.

[49] Prolonged damaging swells from Hurricanes Lane, Olivia, and Norman caused extensive erosion along the north shore of Oʻahu.

[77] Volunteers from All Hands and Hearts, Team Rubicon, and Southern Baptist Disaster Relief helped residents clean flood damage and remove mold.

[62] Officials advised residents to stay out of coastal waters between Hāmākua Coast and Laupāhoehoe along the Big Island on September 4 due to runoff and sewage spills in Hilo Bay.

On August 30 the Maui County Federal Credit Union opened disaster relief programs to fire victims in Lahaina.

[86] The Maui division of Habitat for Humanity assisted residents with rebuilding homes by purchasing appliances and providing vendor discounts, namely with lumber.

[94] The United States Congress allocated $1,195,089.75 to Hawai‘i County on June 11, 2020, for the repair of the Laupahoehoe Gulch Bridge along the Mamalahoa Highway in Hāmākua.

[97] The Hawaii County Department of Public Works announced in September 2021 that it would begin the construction of a temporary bridge over the Makea Stream.