List of Category 5 Pacific hurricanes

A Category 5 hurricane is defined as having sustained windspeeds of at least 137 knots (157 mph; 252 km/h; 70 m/s) over a one-minute period 10 metres (32 ft 10 in) above the ground.[1][2] As a tropical cyclone is moving, its wind field is asymmetric. In the northern hemisphere, the strongest winds are on the right side of the storm (relative to the direction of motion). The highest winds given in advisories are those from the right side.[3]

Since the 1959 season, only 18 hurricanes are known to have reached Category 5 intensity. There are no known Category 5 storms occurring before 1959. It is possible that some earlier storms reached Category 5 over open waters, but they were never recognized because they never affected land and remained at sea.[4]

Hurricane Linda at its peak intensity on September 12, 1997.

Hurricane Patricia shortly after its record peak intensity on October 23, 2015.

This lists all of the Category 5 hurricanes in the order in which they formed. Only 1994's Hurricane Emilia and 2006's Hurricane Ioke have reached Category 5 intensity more than once; that is, by weakening into a Category 4 or weaker storm and later re-strengthening to a Category 5 storm.

Before the advent of reliable geostationary satellite coverage in 1966, the number of eastern Pacific tropical cyclones was significantly underestimated.[5] It is therefore very possible that there are additional Category 5 hurricanes other than those listed, but they were not reported and therefore not recognized. However, the lack of Pacific Category 5 hurricanes during the late 1970s, 1980s, and early 1990s, is certain.[4]

The minimum central pressure of these storms is, for the most part, estimated from satellite imagery using the Dvorak technique. In the case of Kenna,[6] Ava,[7] Patricia, and Lane, the central pressure was measured by hurricane hunter aircraft flying into the storm.[4] Because of the estimation of central pressures, it is possible that other storms more intense than these have formed.[8]

The reason for estimating the pressure (in lieu of direct measurements) is the fact that most of these storms did not threaten land.[9] As Kenna, Patricia and Lane were threatening land, their pressures were measured by Hurricane Hunters using dropsondes.[6] While Hurricane Ava never threatened land,[4] it too was flown into by Hurricane Hunters to test equipment and conduct research.[7]

Older storms have incomplete pressure readings, since there were no satellite-based estimates; the only observations were taken by ships, land-based observations, or reconnaissance aircraft when available. Ava's minimum known pressure was measured when it was a Category 4 hurricane, for example.[4] John and Gilma have incomplete pressures because the Central Pacific Hurricane Center, in general, did not publish pressure on systems in the central Pacific (140°W to the dateline) at the time.[10] This list is not identical to the list of most intense Pacific hurricanes. The most intense known Category 4 storm in the eastern Pacific was 2014's Odile. The lowest pressure of this storm was 918 millibars, lower than that of some Category 5's, such as Guillermo.[4]

Hurricanes have reached Category 5 intensity during every month from June to October. The earliest Category 5 to form in a season is 1973's Hurricane Ava, which formed on June 7. The latest Category 5 to form in a season is Hurricane Kenna, which reached peak intensity on October 24. Hurricanes Ava, Gilma, Ioke, Linda, and Patricia are the most intense storms to form in their respective months. There have been no May, November, or off-season Category 5 hurricanes.[4]

Two Pacific hurricanes are known to have reached Category 5 intensity multiple times: Emilia and Ioke. Both did it twice, and Ioke reached Category 5 status a third time as a typhoon while in the western Pacific.[4] Hurricane Ioke was tied for the longest-lasting Category 5 hurricane recorded, spending 42 hours at that strength,[11] while hurricanes John and Linda had the longest time spent consecutively at that intensity.[4]

Hurricane Hernan off the coast of Mexico on September 1, 2002, at peak strength.

Microwave radar in the tail of a C130 during a flight into Hurricane Ava.

List of Category 5 Pacific hurricanes[4]

Storm name	Season	Dates as a Category 5	Time as a Category 5 (hours)	Peak one-minute sustained winds		Pressure
				mph	km/h	hPa	inHg
Patsy	1959	September 6	6	175	280	930	27.46
Ava	1973	June 7	24	160	260	915	27.02
Emilia	1994	July 19–21	18	160	260	926	27.34
Gilma	1994	July 24–25	18	160	260	920	27.17
John	1994	August 22–24	42	175	280	929	27.43
Guillermo	1997	August 4–5	24	160	260	919	27.14
Linda	1997	September 12–14	42	185	295	902	26.64
Elida	2002	July 25	6	160	260	921	27.20
Hernan	2002	September 1	12	160	260	921	27.20
Kenna	2002	October 24	18	165	270	913	26.96
Ioke	2006	August 24–26	42	160	260	915	27.02
Rick	2009	October 18	24	180	285	906	26.75
Celia	2010	June 25	12	160	260	921	27.20
Marie	2014	August 24	6	160	260	918	27.11
Patricia	2015	October 22–23	23	215	345	872	25.75
Lane	2018	August 22	12	160	260	926	27.34
Walaka	2018	October 1–2	15	160	260	920	27.17
Willa	2018	October 22	6	160	260	925	27.32
For its first time as a Category 5, Emilia was at that intensity for 6 hours; the second time was for 12 for a total of 18 hours.[12] For its first time as a Category 5, Ioke was at that intensity for 18 hours; the second time was 24 additional hours east of the dateline, giving a total of 42 hours.[4] Ioke did not lose Category 5 status on August 26, however, it moved into the Western North Pacific, and thus was no longer considered a hurricane, but rather a typhoon.

Hurricane Walaka, the second of three Category 5 hurricanes during the 2018 season.

In the eastern Pacific, Category 5 hurricanes usually occur only in El Niño years. During El Niño years, conditions are more favorable for tropical cyclones because of warmer sea surface temperatures and reduced wind shear. This is why Category 5 hurricanes cluster in single seasons, with half of the known Category 5 hurricanes (nine) having occurred in the 1994, 2002, and 2018 seasons–the three seasons with the most Category 5 hurricanes, at three each. The effects of El Niño are most significant in the central Pacific (140°W to the dateline).[13]

The general lack of Category 5s in non warm-ENSO years is because of there being limited space for development. The prevailing ocean currents of the area carry warm water to the west. As there is no large piece of land to block the water and cause it to "pile up" like in the Atlantic, the area suitable for all tropical cyclones is small. Farther out to sea, while waters are still warm, wind shear limits the development of tropical cyclones in the waters south of Hawaii. This makes an otherwise ideal region unfavorable for tropical cyclones.

This does not mean that a Category 5 hurricane cannot form outside of an El Niño event. The entire year of 1959 was neither an El Niño or a La Niña, but it had one Category 5 hurricane (Patsy). Most of 1973 was during a La Niña, which reduces tropical cyclone activity in the eastern Pacific, yet Hurricane Ava, a Category 5 hurricane, formed in June of that year.[14] The 2009, 2010, 2014, and 2015 seasons are the only pairs of seasons in which a Category 5 hurricane formed in consecutive years (Rick and Celia, and Marie and Patricia, respectively).[15]

Hurricane Kenna, one of only four Category 5 Pacific hurricanes to make landfall at any intensity.

Of all of the Category 5 Pacific hurricanes, the only ones to make landfall at any intensity were Hurricane Kenna, Hurricane Rick, Hurricane Patricia, and Hurricane Willa. None made landfall as Category 5 hurricanes; Patricia and Kenna had weakened to Category 4 status at the time of their landfalls, Willa had weakened to Category 3, and Rick was a tropical storm at its landfall. Patricia was the strongest at landfall among Pacific hurricanes; 1976's Hurricane Madeline and 1992's Hurricane Iniki are tied as the second-strongest storms at landfall, both of which did not reach Category 5 strength, but made landfall as stronger Category 4 storms than Kenna.[6] Originally, a hurricane in 1959 was thought to have struck Manzanillo at Category 5 intensity, but a reanalysis in 2016 indicated the storm had peaked as a Category 4 hurricane, and made landfall with the same sustained wind speed as Kenna.[16] Patricia was also originally thought to have made landfall as a Category 5 hurricane near Manzanillo before post-season analysis in 2016.

In addition to these four systems, hurricanes John, Linda, Ioke, Lane, and Walaka all threatened land at some point during their existence. John, Ioke and Walaka had minimal impacts on Johnston Atoll, John caused heavy surf in Hawaii, and Walaka passed close to East Island in the French Frigate Shoals.[12] Linda was briefly forecast to approach southern California, and it passed close to Socorro Island near peak intensity.[11][17][18] Out of the five aforementioned hurricanes, Lane had the most significant impact on land, threatening Hawaii as a major hurricane, and dropping more than 40 inches (1,000 mm) of rain across many areas.[19]

The reason for the lack of landfalls is that tropical cyclones in the northern hemisphere usually travel to the west.[20] In the Atlantic, this sends hurricanes towards North America. In the eastern Pacific, this sends tropical cyclones out into the open ocean to dissipate over waters too cool to support them or in environments with high wind shear. Hawaii, the only heavily populated island chain in the eastern Pacific, is protected from most hurricanes by a subtropical ridge and because its land area is small relative to the total ocean area where hurricanes form and travel.

• List of tropical cyclones
• List of the most intense tropical cyclones
• List of Pacific hurricane seasons
• List of Category 5 Atlantic hurricanes
• List of Eastern Pacific tropical storms
• List of Category 1 Pacific hurricanes
• List of Category 2 Pacific hurricanes
• List of Category 3 Pacific hurricanes
• List of Category 4 Pacific hurricanes
• List of F5 and EF5 tornadoes