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 1978 Atlantic hurricane season was a slightly above average hurricane season in terms of number of named storms. Eleven tropical cyclones were named in all, and five of these became hurricanes; two of the five became a major hurricane. This was also the last Atlantic hurricane season to use an all-female naming list. The season officially began on June 1, 1978, and ended on November 30, 1978. These dates, adopted by convention, denote the period in each year when most tropical cyclogenesis occurs in the Atlantic basin. However, the formation of subtropical or tropical cyclones is possible at any time of the year, as shown by the formation of an unnamed subtropical storm on January 18.