These dates conventionally delimit the period of each year when most tropical cyclones form in the northeastern Pacific Ocean.

Moreover, Tropical Storm Bernie also made landfall along the Baja California peninsula, later providing rain to Arizona.

[3][5][6] During the season, tropical cyclone advisories were issued by the Naval Fleet Warning Central (NFWC) in Alameda, which held responsibility for the basin until 1970.

The first tropical cyclone of the season – Hurricane Valerie – was first observed on June 24, about 245 mi (400 km) west of Acapulco, Guerrero.

[3] It moved northwestward along the coast, producing high seas and strong winds in southwestern Mexico.

[3] On August 24, satellite imagery indicated a hurricane with a defined eye was located over the central Pacific Ocean.

It slowly weakened as it moved over lukewarm waters, and deteriorated more rapidly after wind shear increased.

After moving northwestward for two days, the storm turned to the north, striking Baja California on September 6 before dissipating.

[3] The remnant moisture caused severe flash floods in the vicinity of Tucson, with 5 to 7 inches (130 to 180 mm) of precipitation falling over the headwaters of the washes of Santa Rosa, Jackrabbit, and Brawley during a 14- to 15-hour period.

[12] The flooding prompted a disaster declaration by former governor Paul Fannin, which provided funds for the affected people.

The next day, Tropical Storm "Z" passed near Johnston Island during the Operation Dominic I and II nuclear tests, although no impact was reported.

[4]The last storm of the season was Hurricane Doreen, which formed on October 1 off the southwest Mexican coast.

On October 4, Doreen made its closest approach to the southern tip of the Baja California peninsula as it began a motion to the northeast.

[3] Hurricane Doreen was responsible for light rainfall in the U.S. states of Arizona, New Mexico, and West Texas.

Surface observations and satellite imagery indicated the formation of a tropical depression about 275 mi (443 km) north of Palmyra Island on July 29.

The advisories were discontinued 275 nautical miles (509 km) from the South Point of Big Island, where it was no longer considered a threat to shipping lanes or any land masses.