The 1973 Pacific typhoon season was the latest start to the typhoon season on record. It had no official bounds, 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.
The scope of this article is limited to the Pacific Ocean, north of the equator and west of the international date line. Storms that form east of the date line and north of the equator are called hurricanes; see 1973 Pacific hurricane season. Tropical Storms formed in the entire west pacific basin were assigned a name by the Joint Typhoon Warning Center. Tropical depressions in this basin have the "W" suffix added to their number. Tropical depressions that enter or form in the Philippine area of responsibility are assigned a name by the Philippine Atmospheric, Geophysical and Astronomical Services Administration or PAGASA. This can often result in the same storm having two names.
25 tropical depressions formed this year in the Western Pacific, of which 21 became tropical storms. 12 storms reached typhoon intensity, of which 3 reached super typhoon strength.
Tropical Storm Bille, which developed on July 12 east of the Philippines, rapidly strengthened on the 14th and 15th to a 150 mph super typhoon. It tracked due north, fluctuating in intensity for the next 3 days. A building ridge over the Sea of Japan forced Billie to the northwest, where it weakened greatly, first to a tropical storm on the 18th, then to a tropical depression on the 19th as it passes over northeastern China. The storm dissipated on the 20th.
Typhoon Dot struck Hong Kong causing sustained storm force winds, killing one person.
Hainan, Qionghai Jiaji town recorded a minimum central pressure of 937.8 hPa when Marge landfall.Marge killed 903 people in Hainan.
The monsoon trough spawned a tropical depression east of the Philippines on October 1. Under weak steering currents, it meandered westward, where favorable conditions allowed for it to strengthen, first to a tropical storm on the 2nd, then to a typhoon on the 3rd. Nora continued to the northwest, and explosively deepened on the 5th and 6th to a 185 mph super typhoon. At the time, it had a minimum central pressure of 877 millibars, the lowest pressure on record at the time and currently tied for 9th. The typhoon weakened as it headed to the northwest, and struck northeastern Luzon on the 7th as a 115 mph typhoon. Nora continued to the northwest, weakening to a minimal typhoon as it hit southeast China on the 10th. The typhoon caused 18 fatalities, with over $2 million in damage.
27 people were killed when Typhoon Ruth crossed Luzon on October 15 and caused $5 million in damage. Ruth continued to the northwest, and hit Hainan Island and China on the 19th and 20th, respectively.
On November 12 this system emerged in the Bay of Bengal and became Tropical Cyclone 37-73.
One of the strongest tropical cyclones to hit Visayas when it entered on November 20. Tropical Storm Openg affected around 3.4 million people.
Western North Pacific tropical cyclones were named by the Joint Typhoon Warning Center. The first storm of 1973 was named Wilda and the final one was named Vera.