[1] The scope of this article is limited to the Pacific Ocean, north of the equator and west of the International Date Line.

Tropical Storms formed in the entire west Pacific basin were assigned a name by the Joint Typhoon Warning Center.

The first tropical cyclone developed on May 28, marking the fourth latest start to any Pacific typhoon season on record, and the last one dissipated on December 22.

Overall inactivity was caused by an unusually strong La Niña, which also fueled a hyperactive Atlantic hurricane season that year.

[2] The next day, 01W entered the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) area of responsibility and received the local name Akang.

[4] The combination of dry air, strong wind shear, and the storm's proximity to land caused Nichole to quickly weaken to a tropical depression twelve hours after reaching its peak intensity.

The exposed remnants of Nichole executed a clockwise-loop offshore Taiwan before traveling north into mainland China and dissipating.

[2] Rough seas produced by the storm caused four container ships to run aground in Taiwans' Kaohsiung Harbor, none of the crew members were injured.

The depression briefly intensified into a tropical storm, with a peak intensity of 85 km/h (50 mph 1-minute winds) as convection wrapped around the entire center of circulation.

Persistent convection developed around the low[6] and early on August 2, the JTWC began issuing advisories on Tropical Depression 04W.

[9] Typhoon Otto produced heavy rains, amounting to at least 400 mm (15.7 in) in mountainous areas of Taiwan, caused flooding which killed five people.

As Penny strengthened into a tropical storm, it made landfall over Northern Luzon, on August 7, and drifted into the South China sea on the same day.

Strong vertical wind shear on August 8 caused Penny's convection to be displaced to south of the storm, and even exposed the level circulation center for a few hours.

As it moved northward, it brought heavy flooding to Honshū, Japan, amounting to 13 deaths and moderate damage from mudslides across the island.

[15] Severe flooding took place in nearby Abashiri Subprefecture where hundreds of homes were inundated after rivers broke their banks.

Although 09W was a relatively short-lived system, its impact on the affected areas was notable, highlighting the potential dangers of even minor tropical cyclones.

The monsoon trough spawned a low pressure system late on September 14, which developed into Tropical Storm Todd shortly thereafter.

Despite its relatively weak intensity, the system brought heavy rainfall and gusty winds to coastal areas, potentially causing localized flooding and disruptions.

While 12W did not develop into a stronger storm, its impact on the region underscores the importance of monitoring even minor tropical disturbances, as they can still lead to significant weather events.

Typhoon Yanni (Heling) was a powerful tropical cyclone that struck East Asia in late September 1998.

The depression formed in a region with unfavorable environmental conditions, such as strong vertical wind shear, which limited its development and intensity.

A monsoonal low that persisted over the South China Sea began to coalesce on November 10, and on the following day, the system became organized enough to be classified as a depression, receiving the designation 21W by the Joint Typhoon Warning Center.

Although the depression initially struggled due to vertical wind shear displacing convection to the west of the center, gradual improvement in structure led to the system being upgraded into a tropical storm early on November 12 and receiving the name Chip.

Though a weak tropical storm, torrential rains from Dawn triggered catastrophic flooding in Vietnam, killing at least 187 people.

Regarded as the worst cyclone to hit the region in three decades, 500,000 homes flooded, an additional 7,000 were destroyed and an estimated 2 million people were left homeless.

After reaching a peak of 100 mph (160 km/h) winds over the South China Sea, Faith weakened to a tropical storm on December 14 just before making landfall on eastern Vietnam.

Gil made landfall in Thailand as a tropical depression which caused a plane crash at Surat Thani due to bad weather before dissipating on December 13.

Situated within an unfavorable environment, the system struggled to maintain deep convection; however, the following day, it was classified as Tropical Depression 27W by the JTWC.

The Philippine Atmospheric, Geophysical and Astronomical Services Administration uses its own naming scheme for tropical cyclones in their area of responsibility.

This table summarizes all the systems that developed within or moved into the North Pacific Ocean, to the west of the International Date Line during 1998.