This timeline documents all of the events of the 2009–10 South-West Indian Ocean cyclone season which is the period that tropical cyclones formed in the Indian Ocean. Within the Indian Ocean most tropical cyclones form within the cyclone season which began on November 1 and will end on April 30. The scope of this article is limited to tropical cyclones that form in the Indian Ocean 30°E and 90°E to the south of the equator. When a zone of disturbed weather form or moves into the South-West Indian Ocean it is assigned a number and monitored by Météo-France who run the Regional Specialized Meteorological Center (RSMC) on Réunion Island. Should a tropical disturbance intensify and become a moderate tropical storm the two sub-regional tropical cyclone Advisory Centres in Mauritius and Madagascar in conjunction with RSMC La Réunion. The United States Joint Typhoon Warning Center (JTWC) also issue warnings on tropical cyclones in this region assigning a number with an "S" suffix. When monitoring a tropical cyclone the Joint Typhoon Warning Center will assess the cyclones intensity on the Saffir–Simpson hurricane scale whilst RSMC La Réunion, Mauritius and Madagascar use the Southwest Indian Ocean Tropical Cyclone Intensity Scale to assess a tropical cyclones intensity.
Typhoon Guchol, known in the Philippines as Super Typhoon Butchoy, was a powerful tropical cyclone which became the first typhoon to make landfall in Japan on June since 2004. The storm formed as tropical disturbance south-southeast of Pohnpei on June 7, and was upgraded to a tropical depression on June 10. The system later intensified in favorable conditions, and reached typhoon intensity on June 15. It reached peak intensity late on June 17, before making landfall over Japan as a typhoon on June 19. The system became extratropical shortly after traversing Japan and was last noted by the Japan Meteorological Agency on June 22.
The 2016–17 South-West Indian Ocean cyclone season was a below-average season, with five tropical storms, three of which intensified into tropical cyclones. It officially began on November 15, 2016, and ended on April 30, 2017, with the exception for Mauritius and the Seychelles, for which it ended on May 15, 2017. These dates conventionally delimit the period of each year when most tropical and subtropical cyclones form in the basin, which is west of 90°E and south of the Equator. Tropical and subtropical cyclones in this basin were monitored by the Regional Specialised Meteorological Centre in Réunion, though the Joint Typhoon Warning Center issued unofficial advisories.
Typhoon Meranti, known in the Philippines as Super Typhoon Ferdie, was one of the most intense tropical cyclones on record. Impacting the Batanes in the Philippines, Taiwan, as well as Fujian Province in September 2016, Meranti formed as a tropical depression on September 8 near the island of Guam. Tracking to the west northwest, Meranti gradually intensified until September 11, at which point it began a period of rapid intensification. Continuing to rapidly intensify, it became a super typhoon early on September 12, as it passed through the Luzon Strait, ultimately reaching its peak intensity on September 13 with 1-minute sustained winds of 315 km/h (195 mph). Shortly afterwards, it passed directly over the island of Itbayat. Meranti passed to the south of Taiwan as a super typhoon, and began weakening steadily as a result of land interaction. By September 15, it struck Fujian Province as a Category 2-equivalent typhoon, becoming the strongest typhoon on record to impact the province. Upon moving inland, rapid weakening ensued and Meranti became extratropical the next day, dissipating shortly afterwards after it passed to the south of the Korean Peninsula.
The 2018–19 South-West Indian Ocean cyclone season was the costliest and the most active season ever recorded. Additionally, it is also the deadliest cyclone season recorded in the South-West Indian Ocean, surpassing the 1891–92 season in which the 1892 Mauritius cyclone devastated the island of Mauritius, and is mainly due to Cyclone Idai. The season was an event of the annual cycle of tropical cyclone and subtropical cyclone formation in the South-West Indian Ocean basin. It officially began on 15 November 2018, and ended on 30 April 2019, except for Mauritius and the Seychelles, which it ended on 15 May 2019. These dates conventionally delimit the period of each year when most tropical and subtropical cyclones form in the basin, which is west of 90°E and south of the Equator. Tropical and subtropical cyclones in this basin are monitored by the Regional Specialised Meteorological Centre in Réunion.
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.
Intense Tropical Cyclone Kenneth was the strongest tropical cyclone to make landfall in Mozambique since modern records began. The cyclone also caused significant damage in the Comoro Islands and Tanzania. The fourteenth tropical storm, record-breaking tenth tropical cyclone, and ninth intense tropical cyclone of the 2018–19 South-West Indian Ocean cyclone season, Kenneth formed from a vortex that the Météo-France office on La Réunion (MFR) first mentioned on 17 April. The MFR monitored the system over the next several days, before designating it as Tropical Disturbance 14 on 21 April. The disturbance was located in a favorable environment to the north of Madagascar, which allowed it to strengthen into a tropical depression and later a tropical storm, both on the next day. The storm then began a period of rapid intensification, ultimately peaking as an intense tropical cyclone with 10-minute sustained winds of 215 km/h (134 mph) and a minimum central pressure of 934 hPa. At that time, Kenneth began to undergo an eyewall replacement cycle and weakened slightly, before making landfall later that day as an intense tropical cyclone. As a result of land interaction, Kenneth became disorganised as it made landfall and rapidly degenerated thereafter. The storm then shifted southward, with the MFR cancelling all major warnings for inland cities. Kenneth was reclassified as an overland depression after landfall, with the MFR issuing its warning at midnight UTC on 26 April. Thunderstorm activity developed off the coast of Mozambique on 27 April as the system began drifting northward. Kenneth re-emerged off the coast of northern Mozambique on 28 April, before dissipating on the next day.
The 2020–21 South-West Indian Ocean cyclone season was an above-average season which produced 12 named storms, with 7 strengthening into tropical cyclones. The season started with the formation of Cyclone Alicia in the extreme northeast section of the basin on 12 November 2020, just before the official start of the season, which marked the third season in a row in which a tropical cyclone formed before the official start of the season. It officially began on 15 November 2020, and ended with the dissipation of Cyclone Jobo on 24 April, 6 days before the official end on 30 April 2021, with the exception of Mauritius and the Seychelles, which officially ended on 15 May 2021. These dates conventionally delimit the period of each year when most tropical and subtropical cyclones form in the basin, which is west of 90°E and south of the Equator. Tropical and subtropical cyclones in this basin are monitored by the Regional Specialised Meteorological Centre in Réunion and unofficially by the Joint Typhoon Warning Center.
The 2021–22 South-West Indian Ocean cyclone season featured the record latest start for the first system to develop. Despite the late start, it was an above-average season that produced 12 named storms, with 5 becoming tropical cyclones. The season began on 15 November 2021, and ended on 30 April 2022, with the exception for Mauritius and the Seychelles, for which it ended on 15 May 2022. These dates conventionally delimit the period of each year when most tropical and subtropical cyclones form in the basin, which is west of 90°E and south of the Equator. However, tropical cyclones that form at any time between 1 July 2021 and 30 June 2022 will count towards the season total. Tropical and subtropical cyclones in this basin are monitored by the Regional Specialised Meteorological Centre in Réunion and unofficially by the Joint Typhoon Warning Center.
The 2021–22 Australian region cyclone season, despite a high number of tropical lows forming, was slightly below-average in terms of activity, with ten tropical cyclones forming, two of which intensified further into severe tropical cyclones. The season began from 1 November 2021 and ended on 30 April 2022, but a tropical cyclone could form at any time between 1 July 2021 and 30 June 2022 and would count towards the season total. During the season, tropical cyclones will be officially monitored by one of the three tropical cyclone warning centres (TCWCs) for the region which are operated by the Australian Bureau of Meteorology, National Weather Service of Papua New Guinea and the Indonesian Agency for Meteorology, Climatology and Geophysics. The United States Joint Typhoon Warning Center (JTWC) and other national meteorological services including Météo-France and the Fiji Meteorological Service also monitored the basin during the season.
Typhoon Chanthu, known in the Philippines as Super Typhoon Kiko, was the second most intense tropical cyclone worldwide in 2021 after Typhoon Surigae in April. It impacted the Cagayan Valley region of the Philippines and became the strongest typhoon to affect the Batanes province since Typhoon Meranti in 2016. The twenty-ninth tropical depression, fourteenth named storm and fourth typhoon of the 2021 Pacific typhoon season, Chanthu originated from a disturbance well east of the Philippine islands on September 5 which organized into a tropical depression later that day. By the next day, the depression had formed into a mature tropical storm which began to explosively intensify by September 7, featuring a pinhole eye on satellite, characteristic of rapidly intensifying storms. Chanthu became a Category 5-equivalent super typhoon by September 8, the highest category on the Saffir–Simpson scale. Subsequent eyewall replacement cycles caused intensity fluctuations, but on September 10, Chanthu peaked with 1-minute sustained winds of 285 km/h (180 mph) just northeast of extreme northeastern Luzon. The typhoon passed very near the Babuyan Islands before passing directly over Ivana, Batanes as a weakening but still powerful Category 5-equivalent super typhoon. Chanthu continued steadily weakening as it passed just east of Taiwan and eventually stalled just east of Shanghai, China. The storm eventually made its second and final landfall near Ikitsuki, Nagasaki in Japan, before crossing the country's mountainous terrain and becoming an extratropical cyclone on September 18. Chanthu then continued eastward and curved southward, before dissipating on September 20. According to Aon Benfield, economic losses totaled US$30 million.
Severe Tropical Storm Ana was a deadly tropical cyclone that affected the African nations of Madagascar, Malawi and Mozambique and was the third-deadliest tropical cyclone in 2022, after the Western Pacific Tropical Storm Megi and Atlantic Hurricane Ian. The first named storm of the 2021–22 South-West Indian Ocean cyclone season, Ana developed from an area of convection that was designated as Invest 93S northeast of Madagascar.
Intense Tropical Cyclone Batsirai was a deadly tropical cyclone which heavily impacted Madagascar in February 2022, becoming the strongest tropical cyclone to strike Madagascar since Cyclone Enawo in 2017. It made landfall two weeks after Tropical Storm Ana brought deadly floods to the island country in late January. The second tropical disturbance, the first tropical cyclone, and the first intense tropical cyclone of the 2021–22 South-West Indian Ocean cyclone season, Batsirai originated from a tropical disturbance that was first noted on 24 January 2022. It fluctuated in intensity and became a moderate tropical storm on 27 January 2022, after which it unexpectedly rapidly intensified into an intense tropical cyclone. It then weakened and struggled to intensify through the coming days due to present wind shear and dry air, where it weakened after some time. Afterward, it entered much more favorable conditions, rapidly intensified yet again to a high-end Category 4 cyclone on the Saffir–Simpson scale while moving towards Madagascar. The storm underwent an eyewall replacement cycle the next day, and fluctuated in intensity before making landfall in Madagascar as a Category 3 cyclone, later rapidly weakening due to the mountainous terrain on the island.
The 2022–23 South-West Indian Ocean cyclone season was one of the deadliest South-West Indian cyclone seasons on record, mostly due to Cyclone Freddy. It officially began on 15 November 2022, and ended on 30 April 2023, with the exception for Mauritius and the Seychelles, for which it ended on 15 May 2023. These dates conventionally delimit the period of each year when most tropical and subtropical cyclones form in the basin, which is west of 90°E and south of the Equator. However, tropical cyclones can form year-round, and all tropical cyclones that form between 1 July 2022 and 30 June 2023 will be part of the season. Tropical and subtropical cyclones in this basin are monitored by the Regional Specialised Meteorological Centre in Réunion and unofficially by the Joint Typhoon Warning Center. The season was average in terms of the number of systems that formed, with nine systems becoming at least moderate tropical storms, and six reaching tropical cyclone strength. Activity began early, with the first two systems developing in September and October, and ended late with Fabien in May.
The 2022–23 Australian region cyclone season was the fourth consecutive season to have below-average activity in terms of named storms. The season officially started on 1 November 2022 and finished on 30 April 2023, however, a tropical cyclone could form at any time between 1 July 2022 and 30 June 2023 and would count towards the season total, as Tropical Cyclone 01U proved in July 26. During the season, tropical cyclones were officially monitored by one of the three tropical cyclone warning centres (TCWCs) for the region which are operated by the Australian Bureau of Meteorology, National Weather Service of Papua New Guinea and the Indonesian Agency for Meteorology, Climatology and Geophysics. The United States Joint Typhoon Warning Center (JTWC) and other national meteorological services including Météo-France and the Fiji Meteorological Service also monitored the basin during the season.
Tropical Cyclone Cheneso was a strong tropical cyclone that affected Madagascar in January 2023. The fourth tropical storm and fifth tropical cyclone of the 2022–23 South-West Indian Ocean cyclone season, Cheneso developed out of a zone of disturbed weather status which was first monitored at RSMC La Réunion on 17 January. Despite convection wrapping into the curved band pattern, the system formed into a tropical depression on 18 January. The depression strengthened into Severe Tropical Storm Cheneso on the following day. Cheneso made landfall over northern Madagascar and weakened into an inland depression, before emerging into the Mozambique Channel. Cheneso later strengthened into a tropical cyclone on 25 January. The system continued moving southeast, before transitioning into a post–tropical depression on 29 January.
Very Intense Tropical Cyclone Freddy, also known as Severe Tropical Cyclone Freddy, was an exceptionally long-lived, powerful, and deadly tropical cyclone that traversed the southern Indian Ocean for more than five weeks in February and March 2023. Freddy was the longest-lasting tropical cyclone ever recorded worldwide, traveling across the southern Indian Ocean, Mozambique, and Madagascar for 36 days, surpassing the record set by Hurricane John in 1994. Freddy also produced the most Accumulated cyclone energy (ACE) of any individual cyclone. Additionally, it is the third-deadliest tropical cyclone recorded in the Southern Hemisphere, only behind 2019's Cyclone Idai and the 1973 Flores cyclone. Freddy was the third named storm of the 2022–23 Australian region cyclone season, and the second very intense tropical cyclone of the 2022–23 South-West Indian Ocean cyclone season.
The 2023–24 Australian region cyclone season was the fifth consecutive season to have below-average activity in terms of named storms. Despite this, it was the second in a row to have at least five severe tropical cyclones, including Australia's wettest tropical cyclone on record. The season officially started on 1 November 2023 and ended on 30 April 2024, however, a tropical cyclone could form at any time between 1 July 2023 and 30 June 2024 and would count towards the season total. During the season, tropical cyclones were officially monitored by one of the three tropical cyclone warning centres (TCWCs) for the region which are operated by the Australian Bureau of Meteorology, National Weather Service of Papua New Guinea and the Indonesian Agency for Meteorology, Climatology and Geophysics. The United States Joint Typhoon Warning Center (JTWC) and other national meteorological services including Météo-France and the Fiji Meteorological Service will also monitor the basin during the season.
The 2023–24 South-West Indian Ocean cyclone season was an above-average season, including ten named storms, six tropical cyclones and two intense tropical cyclones. Despite its moderate activity, it was the least deadly and destructive season in three years. It is the current event of the annual cycle of tropical and subtropical cyclogenesis. It began on 15 November 2023, and ended on 30 April 2024, with the exception for Mauritius and the Seychelles, where it ended on 15 May 2024. These dates conventionally delimit the period of each year when most tropical and subtropical cyclones form in the basin, which is west of 90°E and south of the Equator. However, tropical cyclones can form year-round, and all tropical cyclones that will form between 1 July 2023 and 30 June 2024 will be part of the season. Tropical and subtropical cyclones in this basin are monitored by the Regional Specialised Meteorological Centre in Réunion and unofficially by the Joint Typhoon Warning Center.
Tropical Cyclone Alvaro was a tropical cyclone that traversed over Madagascar during New Year's Day. The first named storm of the 2023-24 South-West Indian Ocean cyclone season, Alvaro originated as a tropical disturbance at the Mozambique Channel. Being forecasted to develop into a moderate tropical storm, the disturbance was in a favorable environment for intensification. Tracking southeast, the system was upgraded into a tropical depression on December 31. It later intensified into a tropical storm, receiving the name Alvaro. Alvaro continued to move and intensify despite vertical wind shear. On January 1, Alvaro further intensified into a severe tropical storm before making landfall over Morombe District, Madagascar. It weakened back to a tropical depression after passing over the mountainous terrain of the island nation. Alvaro re-entered again to the Indian Ocean and intensified back into a moderate tropical storm. Shortly after reintensification, strong wind shear prevented any further development of the storm. Alvaro later transitioned into a post-tropical depression, being last noted on January 4.
