This timeline documents all of the events of the 2009 Pacific typhoon season which was the period that tropical cyclones formed in the Western Pacific Ocean during 2009, with most of the tropical cyclones forming between May and November. The scope of this article is limited to the Pacific Ocean, north of the equator between 100°E and the International Date Line. Tropical storms that form in the entire Western Pacific basin are assigned a name by the Japan Meteorological Agency. Tropical depressions that form in this basin are given a number with a "W" suffix by the United States' Joint Typhoon Warning Center. In addition, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) assigns names to tropical cyclones that enter or form in the Philippine area of responsibility. These names, however, are not in common use outside of the Philippines.
The September 2009 Vietnam tropical depression was a weak tropical depression that caused deadly flooding throughout central Vietnam in early September. Forming out of an area of low pressure on September 3, the depression hardly intensified as it meandered off the coast of Vietnam. Initially situated in a favorable environment, convective banding features began to develop and shower and thunderstorm activity formed near the center. On September 4, the Joint Typhoon Warning Center issued a Tropical Cyclone Formation Alert; however, a sudden increase in wind shear caused the system to rapidly become disorganized, leading to the cancellation of the alert the next day. The system continued to slowly track off the coast of Vietnam, nearly dissipating on September 5, before becoming better organized. However, the depression remained weak, with the JTWC reporting on September 7 that the depression had dissipated, though the Japan Meteorological Agency (JMA) continued to issue advisories until the depression dissipated during September 9.
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.
The 2017 Pacific typhoon season was a below-average season in terms of accumulated cyclone energy and the number of typhoons and super typhoons, and the first since the 1977 season to not produce a Category 5-equivalent typhoon on the Saffir–Simpson scale. The season produced a total of 27 named storms, 11 typhoons, and only two super typhoons, making it an average season in terms of storm numbers. It was an event in the annual cycle of tropical cyclone formation, in which tropical cyclones form in the western Pacific Ocean. The season runs throughout 2017, though most tropical cyclones typically develop between May and October. The season's first named storm, Muifa, developed on April 25, while the season's last named storm, Tembin, dissipated on December 26. This season also featured the latest occurrence of the first typhoon of the year since 1998, with Noru reaching this intensity on July 23.
The 2020 Pacific typhoon season was the first of an ongoing series of below-average Pacific typhoon seasons, and became the first with below-average tropical cyclone activity since 2014, with 23 named storms, 10 of which became typhoons and only 2 became super typhoons. This low activity was a consequence of La Niña that persisted from the summer of the year. It had the fifth-latest start in the basin on record, slightly behind 1973, and was the first to start that late since 2016. The first half of the season was unusually inactive, with only four systems, two named storms and one typhoon at the end of July. Additionally, the JTWC recorded no tropical cyclone development in the month of July, the first such occurrence since reliable records began. The season's first named tropical cyclone, Vongfong, developed on May 8, while the season's last named tropical cyclone, Krovanh, dissipated on December 24. However, the season's last system was an unnamed tropical depression which dissipated on December 29.
Tropical Depression 18W was a tropical depression that impacted Vietnam, Laos and Thailand during mid September 2013. The system was first noted as a tropical depression on September 16, 2013, while it was located within the South China Sea to the south east of Hanoi in Vietnam. Over the next two days the system gradually developed further, before it was reported by the Vietnamese National Centre for Hydro Meteorological Forecasting that the system had developed into their eighth tropical storm of 2013. However, other meteorological agencies did not report that the system had developed into a tropical storm.
Tropical Storm Mangkhut, known in the Philippines as Tropical Depression Kiko, was a storm that made landfall in Vietnam during August 7 and 8, 2013. Mangkhut, a replacement name for Durian, which is a Thai fruit for mangosteen. The 10th named storm of this season. Shortly after Tropical Storm Jebi made landfall over northern Vietnam, another area of low pressure was recognized northeast of Puerto Princesa, Palawan, the system is also favorable for any intensification. After being named Kiko by PAGASA, the storm consolidated further, resulting in being named Mangkhut as it intensified into a tropical storm. Mangkhut moved north-northwest before making landfall over northern Vietnam. The system later dissipated at Laos on August 8.
Typhoon Lingling, known in the Philippines as Typhoon Nanang, was a deadly typhoon that struck the Philippines and Vietnam in 2001 and caused 379 deaths. The name "Lingling" was given by Hong Kong. The 39th tropical depression, 22nd named storm, and 13th typhoon of the 2001 Pacific typhoon season, Lingling developed into a tropical depression on November 6 and given the local name Nanang by the PAGASA. The next day, it was upgraded into a tropical storm and given the name Lingling by the Japan Meteorological Agency (JMA). Lingling's intensity briefly stagnated as it moved over Visayas before resuming intensification and intensifying into a severe tropical storm on November 8. One day later, both the JMA and the Joint Typhoon Warning Center (JTWC) upgraded Lingling to a typhoon as it exited the Philippine archipelago and moved into the South China Sea. After intensifying into a typhoon, Lingling began to quickly intensify, peaking with 10-min sustained winds of 155 km/h (96 mph) and 1-min sustained winds of 215 km/h (134 mph), with a minimum central pressure of 940 mbar (28 inHg). Lingling began to weaken as it approached the Vietnamese coast, before making landfall on November 11 at 18:00 UTC. Lingling rapidly weakened afterward, dissipating on November 12.
Tropical Storm Kujira was a tropical cyclone that prompted the PAGASA to declare the beginning of the rainy season in the Philippines. The ninth tropical depression, 8th named storm, and first storm to make landfall on China in the 2015 Pacific typhoon season, it formed as a tropical depression south of the Paracel Islands on June 19.
Tropical Storm Vamco was a weak tropical cyclone which affected Indochina in mid-September 2015. Formed from a tropical disturbance on September 13, the system developed into a tropical storm and reached its peak intensity on September 14. Vamco made landfall in Vietnam and affected Laos, Thailand and Cambodia. The storm caused flooding in these countries and damages amounted to US$14.1 million. Fifteen people died in the floods.
Typhoon Damrey, known in the Philippines as Severe Tropical Storm Ramil, was a strong tropical cyclone that affected the Philippines and Vietnam during early November 2017. Damrey first originated as a tropical depression over the Philippine archipelago of Visayas on October 31. Emerging into the South China Sea a few days later, the system strengthened into the second deadliest and twenty-third named storm of the 2017 Pacific typhoon season. Rapidly intensifying, Damrey became the season's tenth typhoon on November 3, reaching its peak intensity as a Category 2 on the same day. Damrey made landfall over Khánh Hoà, Vietnam on November 4 and began to rapidly weaken, fully dissipating on November 5.
The 2021 Pacific typhoon season was the second consecutive to have below-average tropical cyclone activity, with twenty-two named storms, and was the least active since 2011. Nine became typhoons, and five of those intensified into super typhoons. This low activity was caused by a strong La Niña that had persisted from the previous year. The season's first named storm, Dujuan, developed on February 16, while the last named storm, Rai, dissipated on December 21. The season's first typhoon, Surigae, reached typhoon status on April 16. It became the first super typhoon of the year on the next day, also becoming the strongest tropical cyclone in 2021. Surigae was also the most powerful tropical cyclone on record in the Northern Hemisphere for the month of April. Typhoons In-fa and Rai are responsible for more than half of the total damage this season, adding up to a combined total of $2.02 billion.
The 2022 Pacific typhoon season was the third consecutive season to have below-average tropical cyclone activity, with twenty-five named storms forming. Of the tropical storms, ten became typhoons, and three would intensify into super typhoons. The season saw a slightly below average activity by named storm count, although many of the storms were weak and short-lived, particularly towards the end of the season. This low activity was caused by an unusually strong La Niña that had persisted from 2020. The season's first named storm, Malakas, developed on April 6, while the last named storm, Pakhar, dissipated on December 12. The season's first typhoon, Malakas, reached typhoon status on April 12. The season ran throughout 2022, though most tropical cyclones typically develop between May and October. Tropical storms Megi and Nalgae were responsible for more than half of the casualties, while typhoons Hinnamnor and Nanmadol both caused $1 billion in damages.
Tropical Storm Toraji was a weak, short-lived system that impacted Vietnam in November 2018. Forming as the twenty-seventh named storm of the 2018 Pacific typhoon season, Toraji developed as a tropical depression to the southeast of Vietnam on November 16. Quickly organising, the system strengthened into a tropical storm the next day. Toraji rapidly weakened thereafter early on November 18, when the storm made landfall over southeastern Vietnam, later dissipating. The storm's remnants moved into the Gulf of Thailand when Toraji re-organised back into a tropical depression on November 20. However Toraji quickly deteriorated on the same day as it moved closer to the Malay Peninsula.
Tropical Storm Noul, also known in the Philippines as Tropical Storm Leon, was a weak, but deadly tropical cyclone that impacted central Vietnam, which had been affected by Tropical Storm Sinlaku more than one month earlier. Noul originated from a tropical system in the Philippine Sea in September 15. The system was upgraded into a tropical depression later that same day by JMA, with JTWC and PAGASA following suit in 15:00 UTC, with PAGASA assigning the local name Leon to the developing tropical cyclone. As Leon was leaving the area of responsibility, Leon intensified into a tropical storm and was assigned the international name Noul by JMA. Noul would make landfall between Quảng Trị and Thừa Thiên-Huế provinces in September 18 before degenerating into a remnant low over Thailand later that day.
Tropical Storm Nangka, also known in the Philippines as Tropical Depression Nika, was a weak tropical cyclone which impacted Hainan and parts of Indochina, which had been affected by Tropical Storm Linfa just days earlier. Nangka in total caused 4 deaths and 5 missing in China and Vietnam.
The 2020 Central Vietnam floods were a series of floods in Central Vietnam, which also affected some areas in Cambodia and Laos in October and early November 2020. The floods focused heavily in several provinces including Thừa Thiên Huế, Hà Tĩnh, Quảng Bình, Quảng Trị, and Quảng Ngãi. The floods were mainly caused by the seasonal monsoon, though enhanced by numerous tropical cyclones.
Severe Tropical Storm Usagi, known in the Philippines as Tropical Storm Samuel, was a tropical cyclone that affected the Philippines and Southern Vietnam in late November 2018, causing severe damage around the Visayas region and Ho Chi Minh City. The storm formed from a disturbance in the Central Pacific basin on November 3, but did not develop into a tropical storm until almost three weeks later, on November 13. Usagi underwent rapid intensification and peaked in intensity before making its final landfall on Vũng Tàu, Bà Rịa–Vũng Tàu province as a weakening tropical storm on November 25. While never considered as a typhoon by the Japan Meteorological Agency (JMA), the Joint Typhoon Warning Center (JTWC) assessed its intensity to be equivalent to Category 2 status on the Saffir–Simpson scale. Usagi caused one death and ₱52.2 million (US$992,000) in damages in the Philippines, most of which came from agriculture. Usagi caused 3 deaths and ₫925 billion in damages in Vietnam.
Tropical Storm Koguma was a weak tropical cyclone that made landfall in Vietnam, causing minor damage. The fourth named storm of the 2021 Pacific typhoon season, the system was first noted as an area of persistent convection on the South China Sea on June 10, with the JTWC assessing the system in its first advisory as a monsoon depression. Tracking west-northwestward, marginally conductive environmental conditions in the area allowed slight intensification while drifting towards Hainan Island. On the next day, the JMA upgraded the system to a tropical depression as it passed to the south of the territory before the agency upgraded the system to a tropical storm on June 12, being assigned the name Koguma. The JTWC; however still treated the system as a tropical depression until 12:00 UTC that day. It continued to move northwest over the warm waters of the Gulf of Tonkin, eventually making landfall in Vietnam over Thanh Hóa by the end of the same day, rapidly weakening afterward.
Tropical Storm Dianmu was a weak tropical cyclone that caused considerable damage over parts of Mainland Southeast Asia during late-September 2021. The fifteenth named storm of the 2021 Pacific typhoon season, Dianmu originated from an area of low-pressure situated in the South China Sea on September 21. Being first monitored by the Joint Typhoon Warning Center, the system rapidly consolidated to a tropical depression on September 22 as it continued to approach Vietnam before strengthening further to a weak tropical storm, with the Japan Meteorological Agency naming it as "Dianmu". Little intensification occurred before it made landfall on the country with winds of 35 knots. It then rapidly weakened over land and dissipated on September 24 as a tropical cyclone.
