Iniki caused around $1.8 billion (1992 US dollars) in damage and six deaths. At the time, Iniki was among the costliest United States hurricanes, and it remains one of the costliest hurricanes on record in the eastern Pacific. The storm struck just weeks after Hurricane Andrew—the costliest tropical cyclone ever at the time—struck the U.S. state of Florida. It was also one of two Category 4 hurricanes to strike the United States that year, as Andrew made landfall in Florida as a Category 5 just a few weeks earlier.
The Central Pacific Hurricane Center (CPHC) failed to issue tropical cyclone warnings and watches for the hurricane more than 24 hours in advance. It is remarkable that despite the lack of early warning, only six deaths were attributable to the storm. Damage was greatest on Kauai, where the hurricane destroyed over 1,400 houses and severely damaged over 5,000. Though not directly in the path of the hurricane's core, Oahu still experienced moderate damage from wind and storm surge.
Located at the southern periphery of a subtropical ridge, Iniki continued westward and strengthened over the unusually favorable central Pacific; it reached hurricane status on September 9 while 470 miles (760 km) south-southeast of Hilo. The subtropical ridge, which typically keeps hurricanes well away from the Hawaiian Islands, weakened due to an approaching upper level-trough and allowed Iniki to turn to the northwest. With very favorable upper-level outflow and warm water temperatures, Iniki steadily intensified, and attained major hurricane status on September 10 while south-southwest of the island chain.
As Iniki turned to the north, it continued to strengthen, reaching a peak of 145 mph (230 km/h) winds on September 11 while 170 miles (270 km) south-southwest of Poipū on the island of Kauai. It continued rapidly to the north-northeast, and made landfall on south-central Kauai early on the 11th with sustained winds of 145 mph (220 km/h), making Iniki a Category 4 hurricane on the Saffir-Simpson Hurricane Scale. The National Weather Service reported wind gusts of up to 175 mph (280 km/h). The highest recorded wind speed from Hurricane Iniki was a 227 mph (365 km/h)reading from the Navy's Makaha Ridge radar station. According to the Honolulu Advertiser, that remarkable figure was recorded at a digital weather station whose wind gauging equipment blew off after taking the measurement during the storm. After crossing the island, Iniki rapidly accelerated north-northeastward, weakened rapidly, and was absorbed by a cold front as it lost tropical characteristics and became extratropical on September 13 about halfway between Alaska and Hawaii.
A hurricane watch was issued for Kauai early on September 11 and was upgraded to a hurricane warning later that day. Prior to Iniki's arrival in Kauai, 8,000 people were housed in shelters, most of whom remembered Hurricane Iwa 10 years prior. Rather than sending tourists to public shelters, two major hotels kept their occupants in the buildings during the storm's passage. During the evacuation of the island, people left days before to family, friends or shelters. Because schools were cancelled, traffic was light and evacuation was well-executed.
The CPHC issued a tropical storm warning for Oahu on September 11 which was upgraded to a hurricane warning later that day. Though not hit by the hurricane, Iniki's large wind field caused nearly 30,000 people to evacuate to 110 public shelters in Oahu. Public school buildings acted as shelters, and were for refuge only, meaning they did not provide food, cots, blankets, medications or other comfort items. Roughly one-third of Oahu's population participated in the evacuation, though many others went to the house of a family member or friend for shelter. The execution of the evacuations went well, beginning with the vulnerable coastal area. For those in need, vans and buses gave emergency transportation, while police manned certain overused intersections. The two main problems that occurred during the evacuation were lack of parking at shelters and exit routes for the coastlines.
The hurricane nearly struck the Central Pacific Hurricane Center in Honolulu. Had it hit there, Iniki, along with Hurricane Andrew and Typhoon Omar, would have struck each of the three National Weather Service offices responsible for tropical cyclone warnings within a two-month period.
Hurricane Iniki's making landfall during daylight hours, combined with the popularity of camcorders, led many Kauai residents to record much of the damage as it was occurring. The footage was later used to create an hour-long video documentary.
Hurricane Iniki's high winds caused extensive damage in Kauai. 1,421 houses were completely destroyed, and 63 were lost from the storm surge and wave action. 5,152 homes were severely damaged, while 7,178 received minor damage. On the south coast, hotels and condominiums received severe damage as well. A few were restored quickly, though some took several years to be rebuilt. One hotel—the Coco Palms Resort famous for Elvis Presley's Blue Hawaii—never reopened after the hurricane. Destroyed housing across the island left more than 7,000 people homeless after the storm's passage.
Iniki's Category 4 winds also downed 26.5% of the island's transmission poles, 37% of its distribution poles, and 35% of its 800 mile (1300 km) distribution wire system. The entire island lacked electricity and television service for an extended period of time. Electric companies restored only 20% of the island's power service within four weeks of Iniki, while other areas were without power for up to three months. Also affected by the storm was the agricultural sector. Though much of the sugar cane was already harvested, what was left was severely damaged. The winds destroyed tender tropical plants like bananas and papayas and uprooted or damaged fruit and nut trees.
Most of Iniki's damage occurred in Kauai. On the island, one person died when struck by debris, while another lost her life when a portion of her house fell on her. Offshore, two Japanese nationals died when their boat capsized. The reduced death toll was likely due to well-executed warnings and preparation. More than 100 injuries can be attributed to Iniki, though most occurred in the aftermath of the hurricane.
Among those on Kauai was filmmaker Steven Spielberg, who was preparing for the final day of on-location shooting of the movie Jurassic Park. He and his 130 cast and crew remained safely in a hotel during Iniki's passage.
The U.S. Coast Guard station at Nawiliwili Harbor was hard hit by the storm, fatally damaging the service's cutter stationed there. The Coast Guard promptly established a humanitarian response detachment, commanded by Lt. Kenneth Armstrong, which helped to provide medical supplies, food, ice, water, and cash grants to island residents, as well as making temporary repairs to public buildings. Under Armstrong's command, the port was recertified to receive gasoline and diesel fuel, which helped to relieve a major fuel shortage caused by the widespread use of personal electrical generators. A larger DoD contingent, nicknamed "Operation Garden Sweep," provided large scale relief in the form of tent cities, utility repairs, road clearings, and major medical operations.
Immediately after the storm, many were relieved to have survived the worst of the Category 4 hurricane; their complacency turned to apprehensiveness due to lack of information, as every radio station was out and there was no news available for several days. Because Iniki knocked out electrical power for most of the island, communities held parties to necessarily consume perishable food from unpowered refrigerators and freezers. Though food markets allowed those affected to take what they needed, many Kauai citizens insisted on paying. In addition, entertainers from all of Hawaii, including George Harrison (who owned a home on the north shore of Kauai) and the Honolulu Symphony, provided free concerts to the victims.
Looting occurred in the aftermath of Iniki, though it was very minor. A group of Army Corps of Engineers, who experienced the looting of Hurricane Andrew just weeks before, were surprised at the overall calmness and lack of violence on the island. Although electrical power was restored to most of the island approximately six weeks following the hurricane, students returned to Kauai public schools two weeks after the disaster. Kauai citizens remained hopeful for monetary aid from the government or insurance companies, though after six months they felt annoyed with the lack of help. The military effectively provided aid for their immediate needs, though, and help arrived before local officials requested aid.
Amateur radio proved to be extremely helpful during the three weeks after the storm, with volunteers coming from the neighboring islands as well from around the Pacific to assist in the recovery. There was support of local government communications in Lihue in the first week of recovery as well as a hastily-organized effort by local operators to assist with the American Red Cross and their efforts to provide shelters and disaster relief centers across Kauai.
In the months after the storm, many insurance companies left Hawaii. To combat this, State Governor John D. Waihee III enacted the Hurricane Relief Fund in 1993 to help unprotected Hawaii residents. The fund was never needed for another Hawaii hurricane, and it was stopped in 2000 when insurance companies returned to the island.
The name Iniki was retired due to this storm in 1993, and was replaced with Iolana in the Central North Pacific tropical storm list. Because that list is rotated through regardless of year, Iolana has not been used for any storm and is not likely to be used for decades due to the relative rarity of storm formation in the Central Pacific.