List of off-season Pacific hurricanes


There have been 25 recorded tropical and subtropical cyclones in the eastern Pacific basin outside the official Pacific hurricane season. The National Hurricane Center monitors the area from North America westward to 140°W, while the Central Pacific Hurricane Center is from 140°W to the International date line, north of the equator. The National Oceanic and Atmospheric Administration currently defines the season as starting May 15 in the eastern Pacific and June 1 for the central Pacific and ending on November 30 for both regions in each calendar year. Occasionally, however, storms develop in late November and persist until December, such as Hurricane Nina of 1957.
Few off-season tropical cyclones in the east Pacific have affected land, and none of them have made landfall. Only Hurricane Nina caused both property damage and fatalities. The strongest hurricane between December and May was Hurricane Ekeka in 1992, which reached winds of. However, after Tropical Storm Paka crossed the International Date Line, it intensified into a typhoon with winds equivalent to a Category 5 hurricane on the Saffir-Simpson hurricane wind scale. The most recent off-season storm is Tropical Depression One-E in late-April 2020.
The beginning of HURDAT, the official Pacific hurricane database maintained by the NHC, is 1949. Since then, thirteen storms have occurred outside the official bounds of hurricane season in the eastern and central north Pacific, respectively. In addition, the CPHC reports nine off-season storms from 1900–1952 with another off-season tropical cyclone occurring in 1832. There have been documents published in the Monthly Weather Review reporting additional off-season storms within off the Mexican coastline, including one in December.

Chronology

The wind speeds listed are maximum one-minute average sustained winds. The category refers to the intensity on the Saffir–Simpson hurricane wind scale; TS stands for tropical storm, and TD for tropical depression.

StormSeasonDurationPeak classificationMaximum
sustained winds		Notes
Unnamed1832Unknown
1902Unknown
1904Unknown
1904Unknown
1906Unknown
Unnamed1922Unknown
Unnamed1925Unknown
Unnamed1936Unknown
Unnamed1938UnknownThe Monthly Weather Review was uncertain if the storm was a tropical cyclone
Nina1957Category 1 hurricaneCaused $100,000 in damage and four fatalities in Hawaii
Carmen1980Tropical storm
Winnie1983Category 1 hurricaneStrongest east Pacific tropical cyclone in the month of December
Winona1989Tropical storm
Alma1990Category 1 hurricane
Ekeka1992Strongest off-season east Pacific tropical cyclone
Hali1992Tropical storm
One-E1996Tropical stormAssumed to have caused two deaths after the ship Solar Wind was lost at sea
Paka1997Tropical stormLater became a super typhoon in the West Pacific
Omeka2010Tropical stormWas subtropical from December 18 – 20 in central Pacific, was in the western Pacific from December 20 – 22, and tropical on December 22 onward in the central Pacific
Aletta2012Tropical storm
Nine-C2015Tropical depressionLatest formation of a tropical cyclone in the eastern Pacific basin.
Pali2016Category 2 hurricaneEarliest formation of a tropical cyclone in the eastern Pacific basin.
Adrian2017Tropical storm
One-E2018Tropical depression
One-E2020Tropical depressionEarliest formation of a tropical cyclone in the eastern Pacific basin proper.

Impact and records

Several off-season tropical cyclones have affected land. Hurricane Nina in early December 1957 prompted evacuations in Hawaii and caused $100,000 in damage in the state. The storm also killed four people and produced waves. Hurricane Winnie in December 1983 caused minor rainfall in parts of Mexico. The unnamed tropical storm of 1996 was assumed to have killed two people when it sank a trimaran called the Solar Wind. After becoming a typhoon, Paka caused significant damage in the Marshall Islands, Guam, and the Northern Mariana Islands. Overall, Paka caused $580 million in damage, enough to warrant retirement of the name. None of these impacting systems made landfall.
In the official east Pacific hurricane database, which dates back to 1949, the first storm to occur outside of the current season was Hurricane Nina in 1957. In the database, thirteen tropical cyclones have existed between December and May, most recently Hurricane Pali in 2016. Tropical Storm Winona in January 1989 was not listed in the database, despite forming south of Hawaii. In addition, there were at least eight tropical cyclones before the start of the official database, many of which existed near Hawaii. Storms were most likely to occur in December, followed by January and May. Only one cyclone each was reported in the two months of March and April. Of all off-season tropical cyclones, the "Froc Cyclone" lasted longest, spanning 12 days and two calendar years. The year with the most off-season storms was tied between 1904 and 1992, with a total of two tropical cyclones. No Pacific hurricane season had both a pre-season and post-season storm.

Monthly statistics


Month of formationNumber of recorded storms
January4
February1
March1
April2
May 6
December11
Total25


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