The 1978 Pacific typhoon season has no official bounds; it ran year-round in 1978, but most tropical cyclones tend to form in the northwestern Pacific Ocean between June and December. These dates conventionally delimit the period of each year when most tropical cyclones form in the northwestern Pacific Ocean.
32 tropical depressions formed this year in the Western Pacific, of which 29 became tropical storms. 15 storms reached typhoon intensity, of which 1 reached super typhoon strength. Many of the storms either remained at sea or failed to do any damage.
Agnes formed on July 24, made a complete loop, and struck China on July 29 with winds of 55 mph after peaking at 60 mph. It dissipated the 30th. In Hong Kong Tropical Storm Agnes killed 3 people.
Tropical Depression 28 developed October 15. Three and a half days later, it strengthened into a tropical storm. Rita became a typhoon late on October 19. Rita reached Category 5 status on October 23, reaching a minimum central pressure of 880 millibars, only 10 mb higher than Typhoon Tip's record set in 1979. After spending over three consecutive days at that intensity, Rita weakened to a Category 4 and smashed ashore on Luzon. Rita stayed a typhoon during its entire passage over the Philippines and emerged into the South China Sea as a minimal typhoon. Rita then decayed slowly and dissipated as a depression near the coast of Vietnam. The typhoon caused considerable damage and loss of life in the Philippines, though exact numbers are unknown.
Western North Pacific tropical cyclones were named by the Joint Typhoon Warning Center. The first storm of 1978 was named Nadine and the final one was named Winnie. This was the final year using this set of names.
Two Central Pacific systems developed, Tropical Depression 10C and Hurricane Susan. The policy at the time was to use Western Pacific names in the Central Pacific.