Typhoon Ketsana, known in the Philippines as Tropical Storm Ondoy, was the second-most devastating tropical cyclone of the 2009 Pacific typhoon season, causing $1.15 billion in damages and 665 fatalities, only behind Morakot earlier in the season, which caused 956 deaths and damages worth $6.2 billion. Ketsana was the sixteenth tropical storm, and the eighth typhoon of the season. It was the most devastating tropical cyclone to hit Manila, surpassing Typhoon Patsy (Yoling) in 1970.

The 2015 Pacific typhoon season was a slightly above average season that produced twenty-seven tropical storms, eighteen typhoons, and nine super typhoons. The season ran throughout 2015, though most tropical cyclones typically develop between May and November. The season's first named storm, Mekkhala, developed on January 15, while the season's last named storm, Melor, dissipated on December 17. The season saw at least one named tropical system forming in each of every month, the first time since 1965. Similar to the previous season, this season saw a high number of super typhoons. Accumulated cyclone energy (ACE) during 2015 was extremely high, the third highest since 1970, and the 2015 ACE has been attributed in part to anthropogenic warming, and also the 2014-16 El Niño event, that led to similarly high ACE values in the East Pacific.