The 1981 Pacific hurricane season was a slightly below average Pacific hurricane season. The season officially started on May 15 in the eastern Pacific basin and June 1 in the central Pacific basin. Both basins' seasons ended on November 30; these dates conventionally delimit the period during which most tropical cyclones form in the northeastern Pacific Ocean. The first tropical cyclone of the season was designated on May 30, and the final storm of the season, Hurricane Otis, dissipated on October 30. The season produced fifteen named storms and a total of eight hurricanes, which was near normal. However, the total of one major hurricane was below the average of three.
The strongest tropical cyclone of the season was Hurricane Norma, which was a powerful Category 3 hurricane on the Saffir–Simpson Hurricane Scale. The storm caused six deaths – five in Texas, and one in Mexico, due to severe flooding. Additionally, the storm caused $74 million (equivalent to $262.06 million in 2025) in damage, which is credited to significant crop damage and many tornadoes. However, the deadliest tropical cyclone of the season was Tropical Storm Lidia, which made two landfalls – one on the southern tip of the Baja California Peninsula and the other along the shores of Sinaloa in early October. As the result of its heavy rainfall in northwestern Mexico, seventy-three fatalities were reported, along with $80 million in damage.
Seasonal summary
There was an absence in storm activity across the Central Pacific Hurricane Center's area of responsibility, as no storms developed in the basin. However, two tropical cyclones from the eastern Pacific, Greg and Jova, entered the central Pacific, the latter entering as a hurricane. The season produced fifteen named storms and eight hurricanes; both of these numbers were equal to the average. The season's one major hurricane, a storm with winds of at least 111 mph (179 km/h), was below the average of three. There are also at least two tropical depressions that did not strengthen into tropical storms.
Six tropical cyclones made landfall in Mexico. First, Tropical Storm Adrian made landfall 240 mi (390 km) east-southeast of Acapulco, but did not cause any damage. Afterwards, Tropical Storm Irwin made landfall in Baja California Sur, but similarly to Adrian, did not cause any damage. Tropical Storm Knut later made landfall near Mazatlán with winds equivalent to a minimal tropical storm, but no deaths or damage was reported. Tropical Storm Lidia struck about 23 mi (37 km) south of Los Mochis on October 8, with winds of 45 mph (75 km/h). Heavy rainfall associated with the cyclone caused moderate damage in northwestern Mexico, and at least seventy-three deaths can be attributed to the storm. On May 30, an area of intense shower and thunderstorm activity located 270 mi (430 km) south of the Mexican coastline. The second to strike the area in 10 days, Norma was absorbed by a frontal system on October 14. The combined entity produced heavy rainfall and severe weather across Texas, which subsequently led to severe crop damage. The final storm to make landfall on Mexico during the 1981 season was Hurricane Otis. Intensifying into a hurricane by October 26, the hurricane brushed the coast of Jalisco before making landfall near Mazatlán at hurricane intensity on October 30. Otis was the second of two hurricanes to make landfall in the country this season.
Systems
Tropical Storm Adrian
On May 30, an area of intense shower and thunderstorm activity located 270 mi (430 km) to the south of the Mexican coastline intensified into a tropical depression. Drifting towards the north and then east-northeast around an area of high pressure centered off the southern coast of Mexico, the depression began to strengthen over 84 °F (29 °C) water. Twelve hours after formation, the depression strengthened into Tropical Storm Adrian. Reaching a peak intensity of 45 mph (75 km/h), Adrian began to move over slightly cooler ocean temperatures of 81 °F (27 °C) and subsequently began to weaken. After being downgraded to a tropical depression by June 2, data from two cargo ships, the Androemda and Santa Maria, were helpful in locating Adrian's center of circulation as it moved towards the Mexican coastline. On June 4, the system made landfall 240 mi (390 km) east-southeast of Acapulco; however, no damage associated with the tropical cyclone was reported, and Adrian dissipated later that same day.
Hurricane Beatriz
On June 28, the season's second tropical depression formed approximately 400 mi (640 km) east of Clipperton Island. Moving quickly towards the west over warm sea-surface temperatures, the depression strengthened into Tropical Storm Beatriz just twelve hours after formation. Embedded within an area of favorable atmospheric conditions, Beatriz attained hurricane status at 1800 UTC on June 30, and intensified further to attain its first brief peak at 85 mph (137 km/h) by early on June 1. Fluctuating in intensity, Hurricane Beatriz attained its peak intensity for a second time on June 2, only to enter an area of higher wind shear and cooler sea-surface temperatures. Far away from land, Beatriz was downgraded to a tropical storm on June 3, and then further into a tropical depression the following day. The tropical cyclone dissipated on July 4 while located several hundred miles to the west of Baja California Sur.
Since Beatriz briefly posed a threat to Mexico and California, the Hurricane Hunters were put on standby, but no flights were made into the storm. The system did produce wave heights as high as 4 ft (1.2 m) to Southern California; however, impact from the storm was less than anticipated.
Tropical Storm Calvin
An area of disturbed weather located several hundred miles to the south of Acapulco organized into a tropical depression on July 4. Moving towards the west-northwest over warm sea-surface temperatures, the depression intensified into a tropical storm on July 5, receiving the name Calvin. Reaching a peak intensity of 50 mph (85 km/h) later that day, Calvin began to move north-northwest around the western periphery of a high pressure system located over extreme northern Mexico. Calvin then moved over cooler water and subsequently weakened to a minimal tropical storm. Located 98 mi (158 km) south-southeast of Cabo San Lucas on July 8, Calvin further weakened to a tropical depression and turned to the west. The system dissipated the following day. As a dying system, Calvin produced high clouds over California and Arizona.
Hurricane Dora
Based on satellite imagery and data from a nearby ship, Yamazuru, a tropical depression formed far away from land on July 10. Passing 254 mi (409 km) north of Clipperton Island, the depression began to strengthen under favorable atmospheric conditions, and was designated Tropical Storm Dora twelve hours after formation. Moving towards the west-northwest, Dora attained hurricane status on July 13; subsequently, the ship Amestelmolen reported seas of 30 ft (9.1 m), a minimum barometric pressure of 981 mbar (29.0 inHg), and 79 mph (127 km/h) winds as it passed 29 mi (47 km) north of the storm's center. As Dora reached its peak intensity of 90 mph (150 km/h) on July 14, a well-defined eye became apparent on satellite imagery, and the storm turned more towards the west. Cooler ocean temperatures below 74 °F (23 °C) subsequently caused the hurricane to weaken, and it was downgraded to a tropical storm on July 15. The storm's structure further deteriorated the following day, and Dora dissipated over 1,000 mi (1,600 km) southwest of Cabo San Lucas.
Tropical Storm Eugene
Following Dora's dissipation, another tropical depression formed 300 mi (480 km) west of the Mexican coastline. While retaining its intensity, the depression moved west-northwest before bending towards the southwest as it intensified into Tropical Storm Eugene on July 18. Above exceptionally warm sea surface temperatures of 85 °F (29 °C), Eugene slowly intensified. After passing 83 mi (134 km) south of Socorro Island, the storm accelerated west-northwest, reaching a peak intensity of 50 mph (80 km/h) early on June 19. Shortly thereafter, the system began to meander over cooler ocean temperatures, and weakened to a tropical depression on July 20. After changing little in intensity for nearly 24 hours, Eugene dissipated on July 21 while located 700 mi (1,100 km) west of the Baja California Peninsula, over water temperatures of 73 °F (23 °C). There were no reports of any effects attributed to the storm.
Hurricane Fernanda
Fernanda originated from an area of showers and thunderstorms that gained sufficient organization to be designated a tropical depression on August 6. Moving rapidly towards the west, the system passed 126 mi (203 km) north of Clipperton Island. Above warm ocean temperatures, the depression strengthened to become a tropical storm twenty-one hours after formation, and after briefly turning towards the west-northwest, Fernanda attained hurricane status on August 9. A well-defined eye associated with the hurricane became visible, and the system reached its peak intensity as a 105 mph (165 km/h) Category 2 hurricane on the Saffir–Simpson Hurricane Scale on August 10. Turning towards the northwest, Fernanda began to enter an area of cooler ocean temperatures and higher wind shear, subsequently weakening. On August 11, Fernanda was downgraded to a Category 1 hurricane, and then further to a tropical storm later that evening. By midday the following day, Fernanda had become a tropical depression, and dissipated early on August 13.
Hurricane Greg
An area of intense thunderstorm activity left the southern coast of Mexico in mid-August. About 184 mi (296 km) south of Socorro Island, it formed on August 13. Over warm sea surface temperatures, the depression steadily intensified; it was upgraded to Tropical Storm Greg at 1800 UTC. As the storm was moving on the southwest periphery of an area of high pressure, it curved west-northwest. Meanwhile, the storm passed 34 mi (55 km) south of Clarion Island at 2100 UTC on August 14. After turning toward the west, the storm's motion slowed. After maintaining its intensity while still a minimal tropical storm, Greg turned to the west-southwest for a day, only to resume its westerly course. As its speed increased a little, Greg gradually strengthened. Based on data from the ship Chapa, Greg was upgraded into a hurricane early on August 20. However, increased wind shear caused the storm to rapidly weaken back into a tropical storm. At this time, the tropical storm was located over 78 °F (26 °C) water. Shortly thereafter, Greg moved into the Central Pacific Hurricane Center (CPHC)'s area of responsibility. It continued to weaken, and was only a minimal tropical storm by the afternoon of August 21. Although Greg weakened into a depression, it maintained a well-defined center of circulation for an additional 24 hours until dissipating at 1800 UTC on August 22 over 600 mi (970 km) east-northeast of Hawaii.
Hurricane Hilary
Based on a report from a cargo ship, the Eastern Pacific Hurricane Center upgraded a tropical disturbance into a tropical depression roughly 400 mi (640 km) west of the Mexican coast at 2105 UTC on August 21. Four hours later, the system strengthened into Tropical Storm Hilary. After turning towards the west, it passed about 50 mi (80 km) south of Socorro Island. Even though Hilary developed a well-defined eye late on August 23, the cyclone was not upgraded into a hurricane until the next afternoon. Accelerating, Hilary reached its peak strength of 85 mph (140 km/h) while located 250 miles (400 km) west of Cabo San Lucas. Moving west, Hilary began to weaken over 84 °F (29 °C) water. Late on August 28, nearly 24 hours following Hilary's downgrade into a tropical depression, the tropical cyclone dissipated far from land.
Tropical Storm Irwin
A tropical depression formed 155 mi (249 km) west of Acapulco on August 27. Over 85 °F (29 °C) water, the depression intensified into Tropical Storm Irwin the next day. By August 25, Tropical Storm Irwin had peaked in intensity as a moderate tropical storm, then weakened as it moved over 83 °F (28 °C) sea-surface temperatures. Less than 100 mi (160 km) southeast of Baja California, Irwin was downgraded into a depression. Turning west-northwest, Irwin made landfall about 50 mi (80 km) south of La Paz on August 30. After moving offshore the next day, Irwin dissipated. No damage was reported.
Hurricane Jova
Following two weeks of inactivity, a tropical depression formed at 1200 UTC September 14 while located in the middle of the Eastern Pacific. Above very warm ocean temperatures, the depression was upgraded into Tropical Storm Jova six hours later. Jova rapidly intensified, and developed an eye late on September 15. Early on September 17, Jova peaked as a mid-level Category 1 hurricane. After briefly turning to the west-southwest, Jova turned back towards the west while weakened into a tropical storm. On September 19, the cyclone turned west-northwest, and dissipated about 100 miles (160 km) north of Hawaii on September 21. Due to its track just north of Hawaii and rapidly weakening in the Central Pacific, its only effect on the Hawaiian Islands was to disrupt the trade winds, leading to an increase in humidity.