The 2004 Pacific hurricane season was an overall below-average Pacific hurricane season in which there were 12 named tropical storms, all of which formed in the eastern Pacific basin. Of these, 6 became hurricanes, and 3 of those intensified into major hurricanes. No storms made landfall in 2004, the first such occurrence since 1991. In addition to the season's 12 named storms, there were five tropical depressions that did not reach tropical storm status. One of them, Sixteen-E, made landfall in northwestern Sinaloa. The season officially began on May 15 in the eastern Pacific, and on June 1 in the central Pacific basin. It officially ended in both basins on November 30. These dates conventionally delimit the period during each year when most tropical cyclones form in each respective basin. These dates conventionally delimit the period during each year when a majority of tropical cyclones form. The season was reflected by an accumulated cyclone energy (ACE) index of 71 units.
The 2005 Pacific hurricane season was a near-average Pacific hurricane season which produced fifteen named storms, seven hurricanes and two major hurricanes. It was also the second consecutive season in which no tropical cyclone of at least tropical storm intensity made landfall. The season officially began on May 15 in the East Pacific Ocean, and on June 1 in the Central Pacific; they ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the Pacific basin. However, the formation of tropical cyclones is possible at any time of the year.
The 2003 Pacific hurricane season was the first season to feature no major hurricanes since 1977. The season officially began on May 15, 2003 in the Eastern North Pacific, and on June 1 in the Central ; both ended on November 30. These dates, adopted by convention, historically describe the period in each year when most tropical cyclogenesis occurs in these regions of the Pacific. The season featured 16 tropical storms, 7 of which intensified into hurricanes, which was then considered an average season. Damage across the basin reached US$129 million, and 23 people were killed by the storms.
The 1993 Pacific hurricane season included more than double the average number of major hurricanes – Category 3 or stronger cyclones on the Saffir–Simpson scale. This activity was the result of an El Niño event, which is the main factor contributing to above-average activity across the Pacific basin. The season featured 15 named storms, 11 hurricanes, and 9 major hurricanes. While the number of named storms was near the long-term average, the number of hurricanes was above the average of 8, and the number of major hurricanes far exceeded the long-term average of 4. Seasonal activity began on May 17 and ended on November 8, within the confines of a traditional hurricane season which begins on May 15 in the East Pacific and June 1 in the Central Pacific. The season ends on November 30 in both basins. These dates conventionally delimit the period during each year when most tropical cyclones form.
The 1986 Pacific hurricane season featured several tropical cyclones that contributed to significant flooding to the Central United States. The hurricane season officially started May 15, 1986, in the eastern Pacific, and June 1, 1986 in the central Pacific, and lasted until November 30, 1986 in both regions. These dates conventionally delimit the period of each year when most tropical cyclones form in the northeastern Pacific Ocean. A total of 17 named storms and 9 hurricanes developed during the season; this is slightly above the averages of 15 named storms and 8 hurricanes, respectively. In addition, 26 tropical depressions formed in the eastern Pacific during 1986, which, at the time, was the second most ever recorded; only the 1982 Pacific hurricane season saw a higher total.
The 1985 Pacific hurricane season is the third-most active Pacific hurricane season on record. It officially started on May 15, 1985, in the eastern Pacific, and on June 1, 1985, in the central Pacific, and lasted until November 30, 1985. These dates conventionally delimit the period of each year when most tropical cyclones form in the northeastern Pacific Ocean. At the time, the 1985 season was the most active on record in the eastern north Pacific, with 28 tropical cyclones forming. Of those, 24 were named, 13 reached hurricane intensity, and 8 became major hurricanes by attaining Category 3 status or higher on the Saffir–Simpson scale. At that time, the 24 named storms was a record; however, this record was broken seven years later in 1992, and was therefore recognized as the second busiest season within the basin, until it was surpassed exactly thirty years later by the 2015 season.
The 1984 Pacific hurricane season featured numerous tropical cyclones, several of which were impactful to land. It was a busy hurricane season with 21 named storms, 13 hurricanes, and 7 major hurricanes, the latter of which are Category 3 or stronger cyclones on the Saffir–Simpson scale. This activity was unusual given the presence of a La Niña, which typically suppresses Central and East Pacific tropical cyclone activity, and only average sea surface temperatures. Seasonal activity began on May 17 and ended on November 8. This lies within the confines of a traditional hurricane season which begins on May 15 in the East Pacific and June 1 in the Central Pacific, and ends on November 30 in both basins. These dates conventionally delimit the period during each year when most tropical cyclones form.
The 1977 Pacific hurricane season stands alongside 2010 as the least active Pacific hurricane season since reliable records began in 1971. Only eight tropical storms formed throughout the year; four further intensified into hurricanes, yet none strengthened into major hurricanes—a Category 3 or stronger on the Saffir–Simpson scale—an occurrence not seen again until 2003. Most tropical cyclones remained over the open eastern Pacific; however, the remnants of hurricanes Doreen and Heather led to heavy rainfall which damaged or destroyed structures and flooded roadways throughout the Southwest United States. Notably, Hurricane Anita which originally formed in the Gulf of Mexico made the rare trek across Mexico into the eastern Pacific, briefly existing as a tropical depression. Eight deaths were recorded while damage reached $39.6 million.
The 1979 Pacific hurricane season was an inactive North Pacific hurricane season, featuring 10 named storms, 6 hurricanes, and 4 major hurricanes. All tropical cyclone activity this season was confined to the Eastern Pacific, east of 140°W. For the first time since 1977, no tropical cyclones formed in, or entered into the Central Pacific, between 140°W and the International Date Line.
The 1975 Pacific hurricane season officially started May 15, 1975, in the eastern Pacific, and June 1, 1975, in the central Pacific, and lasted until November 30, 1975. These dates conventionally delimit the period of each year when most tropical cyclones form in the northeast Pacific Ocean.
The 1978 Pacific hurricane season was the first Pacific hurricane season to use both masculine and feminine names for tropical cyclones. It also began the modern practice of utilizing naming lists every six years. Despite lacking an El Niño, a common driver of enhanced activity in the East and Central Pacific basins, the 1978 season was active. It featured 19 named storms, 14 hurricanes, and 7 major hurricanes, the latter of which are Category 3 or stronger cyclones on the Saffir–Simpson scale. Within the confines of the Central Pacific basin, located between the International Date Line and 140°W, 13 tropical cyclones or their remnants were observed by forecasters at the Central Pacific Hurricane Center, a record number of occurrences at the time. Seasonal activity began on May 30 and ended on October 21, within the limits of a traditional hurricane season which begins on May 15 in the East Pacific and June 1 in the Central Pacific. The season ends on November 30 in both basins. These dates conventionally delimit the period during each year when most tropical cyclones form.
The 2011 Pacific hurricane season was a below average season in terms of named storms, although it had an above average number of hurricanes and major hurricanes. During the season, 13 tropical depressions formed along with 11 tropical storms, 10 hurricanes and 6 major hurricanes. The season officially began on May 15 in the East Pacific Ocean, and on June 1 in the Central Pacific; they both ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the Pacific basin. The season's first cyclone, Hurricane Adrian formed on June 7, and the last, Hurricane Kenneth, dissipated on November 25.
The 2012 Pacific hurricane season was a moderately active Pacific hurricane season that saw an unusually high number of tropical cyclones pass west of the Baja California Peninsula. The season officially began on May 15 in the eastern Pacific Ocean, and on June 1 in the central Pacific (from 140°W to the International Date Line, north of the equator; they both ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in these regions of the Pacific Ocean. However, the formation of tropical cyclones is possible at any time of the year. This season's first system, Tropical Storm Aletta, formed on May 14, and the last, Tropical Storm Rosa, dissipated on November 3.
The 2013 Pacific hurricane season was an above average Pacific hurricane season with 21 tropical cyclones forming. Of these, 20 became named storms – 18 in the Eastern Pacific basin, and 2 in the Central Pacific basin. Of the 18 named storms in the east, 9 became hurricanes, with one, Raymond, becoming the season's only major hurricane. In the central, neither named storm became a hurricane. It was also a below-normal season in terms of Accumulated cyclone energy (ACE), as many of its systems were weak and short-lived. The season officially began on May 15 in the Eastern Pacific and started on June 1 in the Central Pacific; both ended on November 30. These dates conventionally delimit the period of each year when most tropical development occurs in these North Pacific basins. The first cyclone, Tropical Storm Alvin, formed on May 15, and the last, Tropical Storm Sonia, dissipated on November 4. It was below average only Category 3 storm was since 1981.
The 2014 Pacific hurricane season was one of the busiest and costliest Pacific hurricane seasons since the keeping of reliable records began in 1949. The season officially started on May 15 in the East Pacific Ocean, and on June 1 in the Central Pacific; they both ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in these regions of the Pacific.
The 2015 Pacific hurricane season is the second-most active Pacific hurricane season on record, with 26 named storms, only behind the 1992 season. A record-tying 16 of those storms became hurricanes, and a record 11 storms further intensified into major hurricanes throughout the season. The Central Pacific, the portion of the Northeast Pacific Ocean between the International Date Line and the 140th meridian west, had its most active year on record, with 16 tropical cyclones forming in or entering the basin. Moreover, the season was the third-most active season in terms of accumulated cyclone energy, amassing a total of 290 units. The season officially started on May 15 in the Eastern Pacific and on June 1 in the Central Pacific; they both ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the Northeast Pacific basin. However, the formation of tropical cyclones is possible at any time of the year. This was shown when a tropical depression formed on December 31. The above-average activity during the season was attributed in part to the very strong 2014–2016 El Niño event.
The 2010 Pacific hurricane season was one of the least active seasons on record, featuring the fewest named storms since 1977. The season officially started on May 15 in the eastern Pacific—east of 140°W—and on June 1 in the central Pacific—between the International Date Line and 140°W—and lasted until November 30. These dates typically cover the period of each year when most tropical cyclones form in the eastern Pacific basin. The season's first storm, Tropical Storm Agatha, developed on May 29; the season's final storm, Tropical Storm Omeka, degenerated on December 21.
The 2019 Pacific hurricane season was an above average season which produced nineteen named storms, most of which were rather weak and short-lived. Only seven hurricanes formed, the fewest since 2010. The season officially began on May 15 in the East Pacific Ocean, and on June 1 in the Central Pacific; they both ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the Pacific basin. This season was one of the latest-starting Pacific hurricane seasons on record, with the first tropical cyclone, Hurricane Alvin, forming on June 25. The final system, Tropical Depression Twenty-One-E, dissipated on November 18.
The 2020 Pacific hurricane season was a near average Pacific hurricane season in terms of named storms, featuring 17, but well below average season for hurricanes and major hurricanes, with only 4 hurricanes and 3 major hurricanes forming. Additionally, no tropical cyclones formed in the Central Pacific basin for the first time since 2017. The season officially began on May 15 in the East Pacific Ocean, and on June 1 in the Central Pacific (from 140°W to the International Date Line, north of the equator; they both ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the respective regions. However, the formation of tropical cyclones is possible at any time of the year, as illustrated in 2020 by the formation of the season's first system, Tropical Depression One-E, on April 25. This was the earliest formation of a tropical cyclone on record in the eastern Pacific basin proper. The final system of the season was Tropical Storm Polo, which dissipated on November 19.
The 2021 Pacific hurricane season was a moderately active Pacific hurricane season, with above-average activity in terms of number of named storms, but below-average activity in terms of major hurricanes, as 19 named storms, 8 hurricanes, and 2 major hurricanes formed in all. It also had a near-normal accumulated cyclone energy (ACE). The season officially began on May 15, 2021 in the Eastern Pacific Ocean, and on June 1, 2021, in the Central Pacific in the Northern Hemisphere. The season ended in both regions on November 30, 2021. These dates historically describe the period each year when most tropical cyclogenesis occurs in these regions of the Pacific and are adopted by convention. However, the formation of tropical cyclones is possible at any time of the year, as illustrated by the formation of Tropical Storm Andres on May 9, which was the earliest forming tropical storm on record in the Eastern Pacific. Conversely, 2021 was the second consecutive season in which no tropical cyclones formed in the Central Pacific.
