The 1948 Pacific typhoon season is an event in the annual cycle of tropical cyclone formation, in which tropical cyclones form in the western Pacific Ocean. The season runs throughout 1948, though most tropical cyclones typically develop between May and October. The scope of this article is limited to the Pacific Ocean to the north of the equator between 100°E and 180th meridian. Within the northwestern Pacific Ocean, there are two separate agencies that assign names to tropical cyclones which can often result in a cyclone having two names. The Japan Meteorological Agency (JMA) will name a tropical cyclone should it be judged to have 10-minute sustained wind speeds of at least 65 km/h (40 mph) anywhere in the basin, whilst the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) assigns names to tropical cyclones which move into or form as a tropical depression in their area of responsibility located between 135°E and 115°E and between 5°N–25°N regardless of whether or not a tropical cyclone has already been given a name by the JMA. Tropical depressions that are monitored by the United States' Joint Typhoon Warning Center (JTWC) are given a number with a "W" suffix.
Typhoon Karen, the strongest cyclone of the season and the one of the earliest recorded if not the earliest super typhoon, developed on January 11, well west of the Philippines. It curved westward while slowly intensifying. After a prolonged period of the slow intensification, the tropical cyclone began to rapidly strengthen. It became a super typhoon on January 16. Shortly after, it weakened and dissipated on January 19.
Tropical Storm Dolores was tracked by the Air Weather Service located on Guam. At one point, a tropical storm was identified and assigned the name Eunice. Post analysis showed that Tropical Storm Dolores was north of the forecast location and actually the system assigned the name Eunice.
A Tropical Storm formed on September 11 and soon turned toward Japan as it gained strength. Ione soon reached category 4 intensity on September 14. Ione then began to lose strength and became a category 1 on September 16. Then, Ione struck Japan in that day killing 838 people. Ione further weakened and became a Tropical Storm on the 17th. Ione then dissipated.
Between 23 July and 4 August, the name Annabell was assigned to a North West Pacific system. The Air Weather Service issued a bulletin issued and tropical cyclone named on what was later determined to be "trough activity"