Traditionally, areas of tropical cyclone formation are divided into seven basins. These include the north Atlantic Ocean, the eastern and western parts of the northern Pacific Ocean, the southwestern Pacific, the southwestern and southeastern Indian Oceans, and the northern Indian Ocean. The western Pacific is the most active and the north Indian the least active. An average of 86 tropical cyclones of tropical storm intensity form annually worldwide, with 47 reaching hurricane/typhoon strength, and 20 becoming intense tropical cyclones, super typhoons, or major hurricanes.
The 1997 North Indian Ocean cyclone season had no bounds, but cyclones tend to form between April and December, with peaks in May and November. These dates conventionally delimit the period of each year when most tropical cyclones form in the northern Indian Ocean.
The 1999 North Indian Ocean cyclone season was an event in the annual cycle of tropical cyclone formation. The North Indian Ocean cyclone season has no official bounds, but cyclones tend to form between April and December, with peaks in May and November. These dates conventionally delimit the period of each year when most tropical cyclones form in the northern Indian Ocean.
During 2005, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year, a total of 141 systems formed with 94 of these developing further and were named by the responsible warning centre. The strongest tropical cyclone of the year was Hurricane Wilma, which was estimated to have a minimum barometric pressure of 882 hPa (26.05 inHg). 2005 was above-average in terms of the number of storms. The most active basin in the year was the North Atlantic, which documented 28 named systems. The Western Pacific had an near-average season with 23 named storms. The Eastern Pacific hurricane season experienced an above-average number of tropical storm intensity systems, numbering 15. Activity across the southern hemisphere's three basins – South-West Indian, Australian, and South Pacific – was fairly significant, with the regions recording 23 named storms altogether, with the most intense Southern Hemisphere cyclone of the year, Cyclone Percy from the South Pacific Ocean basin peaking at 145 mph (235 km/h) and 900 millibars. Throughout the year, 28 Category 3 tropical cyclones formed, including eight Category 5 tropical cyclones in the year. The accumulated cyclone energy (ACE) index for the 2005, as calculated by Colorado State University was 899.6 units.
During 2007, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year, a total of 129 systems formed with 79 of these developing further and were named by the responsible warning centre. The strongest tropical cyclone of the year was Cyclone George, which was estimated to have a minimum barometric pressure of 902 hPa (26.64 inHg). The deadliest tropical cyclone of the year was Cyclone Sidr in the North Indian Ocean which killed 15,000 people in Bangladesh. The costliest tropical cyclone of the year was Cyclone Gonu in the North Indian Ocean, which caused more than $4.41 billion in damage after striking Oman, United Arab Emirates, Iran and Pakistan. The most active basin in the year was the Western Pacific, which documented 24 named systems. The North Atlantic had an above-average season with 15 named storms. The Eastern Pacific hurricane season experienced a below-average number of tropical storm intensity systems, numbering 11. Activity across the Southern Hemisphere's three basins – South-West Indian, Australian, and South Pacific – was fairly significant, with the regions recording 25 named storms altogether, with the most intense storm of the year coming from the Australian basin. Throughout 2007, twenty one major tropical cyclones formed, including five Category 5 tropical cyclones in the year. The accumulated cyclone energy (ACE) index for the 2007, as calculated by Colorado State University was 568.1 units.
During 2018, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year, a total of 151 tropical cyclones had formed this year to date. 102 tropical cyclones were named by either a Regional Specialized Meteorological Center (RSMC) or a Tropical Cyclone Warning Center (TCWC).
During 2017 tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year, a total of 146 tropical cyclones had formed. 88 tropical cyclones had been named by either a Regional Specialized Meteorological Center (RSMC) or a Tropical Cyclone Warning Center (TCWC). The strongest and deadliest tropical cyclone was Hurricane Maria with a minimum barometric pressure of 908 mbar and killing 3,000 people in Puerto Rico and Dominica. The costliest tropical cyclone of the year was Hurricane Harvey in the Atlantic, which struck Houston metropolitan area in August causing US$125 billion in damage, tying with Hurricane Katrina as the costliest tropical cyclone worldwide.
During 2019, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year,a total of 142 systems formed, with 100 of these developing further and being named by the responsible warning centre. The strongest tropical cyclone of the year was Typhoon Halong, with a minimum barometric pressure of 905 hPa (26.72 inHg). Cyclone Idai became the deadliest tropical cyclone of the year, after killing at least 1,303 people in Mozambique, Malawi, Zimbabwe, and Madagascar. The costliest tropical cyclone of the year was Typhoon Hagibis, which caused more than $15 billion in damage after striking Japan.
During 2016, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year, 140 tropical cyclones formed in bodies of water known as tropical cyclone basins. Of these, 84, including two subtropical cyclones in the South Atlantic Ocean and two tropical-like cyclones in the Mediterranean, were named by various weather agencies when they attained maximum sustained winds of 35 knots. The strongest storm of the year was Winston, peaking with a pressure of 884 hPa (26.10 inHg) and with 10-minute sustained winds of 285 km/h (175 mph) before striking Fiji. The costliest and deadliest tropical cyclone in 2016 was Hurricane Matthew, which impacted Haiti, Cuba, Florida, Georgia and the Carolinas, causing US$15.09 billion in damage. Matthew killed 603 people; 546 in Haiti, 47 in United States, 4 in Cuba and Dominican Republic, and 1 in Colombia and St. Vincent.
2020 was regarded as the most active tropical cyclone year on record, documenting 104 named tropical systems. During the year, 142 tropical cyclones formed in bodies of water known as tropical cyclone basins. Of these, a record-high of 104, including three subtropical cyclones in the South Atlantic Ocean and three tropical-like cyclones in the Mediterranean, were named by various weather agencies when they attained maximum sustained winds of 35 knots. The strongest storm of the year was Typhoon Goni, peaking with a pressure of 905 hPa (26.72 inHg). The deadliest storm of the year was Hurricane Eta which caused 175 fatalities and another 100+ to be missing in Central America and the US, while the costliest storm of the year was Hurricane Laura, with a damage cost around $19.1 billion in the Greater Antilles, The Bahamas, and the Gulf Coast of the United States.
Throughout 2009, 130 tropical cyclones formed in bodies of water known as tropical cyclone basins. Of these, 81 were named, including a subtropical cyclone in the South Atlantic Ocean, by various weather agencies when they attained maximum sustained winds of 35 knots. The strongest storm of the year was Typhoon Nida in the Western Pacific Ocean. The deadliest and costliest storm of the year was Typhoon Morakot (Kiko) causing 789 fatalities through its track in the Philippines, Japan, Taiwan, China, and the Korean peninsula. Throughout the year, twenty-one Category 3 tropical cyclones formed, including five Category 5 tropical cyclones in the year. The accumulated cyclone energy (ACE) index for the 2009, as calculated by Colorado State University was 609.6 units.
During 2000, tropical cyclones formed in seven different areas called basins, located within various parts of the Atlantic, Pacific, and Indian Oceans. A total of 140 tropical cyclones formed within bodies of water known as tropical cyclone basins, with 81 of them being further named by their responsible weather agencies when they attained maximum sustained winds of 35 knots. The strongest storm of the year was Cyclone Hudah, peaking with a minimum pressure of 905 hPa (26.72 inHg), and with 10-minute sustained winds of 220 km/h (135 mph). The highest confirmed number of deaths from a storm was from Typhoon Kai-tak, which killed 188 people, however, Leon–Eline may have killed up to 722 people. The costliest storm was Saomai, which caused $6.3 billion in damage. The accumulated cyclone energy (ACE) index for the 2000, as calculated by Colorado State University was 677.3 units.
The year 1997 was regarded as one of the most intense tropical cyclone years on record, featuring a record 12 category 5-equivalent tropical cyclones, according to the Saffir–Simpson hurricane wind scale. The year also featured the second-highest amount of accumulated cyclone energy (ACE) on record, just behind 1992 and 2018. Throughout the year, 108 tropical cyclones have developed in bodies of water, commonly known as tropical cyclone basins. However, only 89 tropical cyclones were of those attaining 39 mph or greater, falling just below the long term average of 102 named systems. The most active basin was the Western Pacific, attaining an ACE amount of 571, the highest ever recorded in any season in any basin on record. The deadliest tropical cyclone was Severe Tropical Storm Linda (Openg). The costliest tropical cyclone was Super Typhoon Winnie (Ibiang), which set a record for having the largest eye on record. The most intense tropical cyclone was Hurricane Linda, peaking at 902 hPa/mbar. Typhoon Paka (Rubing), the longest-lived system, produced the fourth-highest ACE for a single tropical cyclone, just behind Typhoon Nancy (1961), Hurricane/Typhoon Ioke (2006), and Cyclone Freddy (2023). The accumulated cyclone energy (ACE) index for the 1997, as calculated by Colorado State University was 1,099.2 units.
During 1999, tropical cyclones formed within seven different bodies of water called basins. To date, 142 tropical cyclones formed in bodies of water known as tropical cyclone basins, of which 72 were given names by various weather agencies. The strongest tropical cyclone of the year was Gwenda, attaining maximum sustained winds of 120 knots and a pressure of 900 hPa (26.58 inHg), later tied with Inigo in 2003. Floyd was the costliest tropical cyclone of the year, with around $6.5 billion worth of damages as it affected the Bahamas, the East Coast of the United States, and the Atlantic Canada. The deadliest cyclone of this year was the 1999 Odisha cyclone, which was blamed for over 9,667 deaths as it devastated India. It was also the strongest Northern Hemisphere cyclone of the year with the pressure of 912 hPa (26.93 inHg) and third most intense tropical cyclone worldwide next to Cyclone Gwenda and Cyclone Vance. Three Category 5 tropical cyclones were formed in 1999. The accumulated cyclone energy (ACE) index for the 1999, as calculated by Colorado State University was 606.4 units.
During 1998, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific, and Indian Oceans. A total of 125 tropical cyclones formed, with 72 of them being named by various weather agencies when they attained maximum sustained winds of 35 knots. The strongest tropical cyclones were Zeb, Ron and Susan which peaked with a pressure of 900 hPa (26.58 inHg). Hurricane Mitch of late October was the deadliest tropical cyclone, killing 11,000 people as it catastrophically affected Central America, and Mexico as a Category 5 major hurricane. Meanwhile, Georges became the costliest, with the damages amounting to $9.37 billion, which also became the costliest in the history of the Dominican Republic and the country of Saint Kitts and Nevis. Throughout the year, four Category 5 tropical cyclones formed. The accumulated cyclone energy (ACE) index for the 1998, as calculated by Colorado State University was 773.1 units.
During 1993, tropical cyclones formed within seven different bodies of water called basins. To date, 110 tropical cyclones formed, of which 78 were given names by various weather agencies. Only one Category 5 tropical cyclone was formed in 1993. The accumulated cyclone energy (ACE) index for the 1993, as calculated by Colorado State University was 710.4 units.
During 2021, tropical cyclones formed in seven major bodies of water, commonly known as tropical cyclone basins. Tropical cyclones will be assigned names by various weather agencies if they attain maximum sustained winds of 35 knots. During the year, 136 systems have formed and 94 were named, including one subtropical depression and excluding one system, which was unofficial. One storm was given two names by the same RSMC. The most intense storm of the year was Typhoon Surigae, with maximum 10-minute sustained wind speeds of 220 km/h (140 mph) and a minimum pressure of 895 hPa (26.43 inHg). The deadliest tropical cyclone was Typhoon Rai, which caused 410 fatalities in the Philippines and 1 in Vietnam, while the costliest was Hurricane Ida, which caused an estimated $75.25 billion USD in damage after striking Louisiana and the Northeastern United States.
During 2022, tropical cyclones formed in seven major bodies of water, commonly known as tropical cyclone basins. Tropical cyclones were named by various weather agencies when they attained maximum sustained winds of 35 knots. During the year, 133 systems formed, of which 87 were named. The strongest storm to form was Typhoon Nanmadol, with minimum pressure of 910 hPa (26.87 inHg). The deadliest tropical cyclone was Tropical Storm Megi, which caused 214 fatalities in the Philippines, while the costliest was Hurricane Ian, which had an estimated damage total of at least $113.1 billion after affecting Trinidad and Tobago, Venezuela, Colombia, the western part of the Greater Antilles and Southeast United States.
In 2024, tropical cyclones will form in seven major bodies of water, commonly known as tropical cyclone basins. Tropical cyclones will be named by various weather agencies when they attain maximum sustained winds of 35 knots. So far, 89 systems have formed, with 64 of them being named. The most intense storm of the year so far is Hurricane Milton, with a minimum barometric pressure of 897 hPa (26.49 inHg). Typhoon Yagi is the deadliest and second-costliest tropical cyclone to date, with at least 830 fatalities and a damage total of $16.5 billion; the costliest tropical cyclone so far is Hurricane Helene, which caused at least $38.5 billion worth of damage in the Southeastern United States.
During 2023, tropical cyclones formed in seven major bodies of water, commonly known as tropical cyclone basins. They were named by various weather agencies when they attained maximum sustained winds of 35 knots. Throughout the year, a total of 115 systems formed, with 79 of them being named. The most intense storm this year was Typhoon Mawar, which had a minimum pressure of 900 hPa (26.58 inHg). The deadliest tropical cyclone of the year was Storm Daniel, which killed at least 5,591 people in Libya, Greece, Turkey, and Bulgaria. Meanwhile, the costliest tropical cyclone was Typhoon Doksuri which caused at least US$28.4 billion worth of damage in China, the Philippines and Taiwan, becoming the costliest on record outside the Atlantic Ocean basin. Among this year's systems, thirty became major tropical cyclones, of which ten intensified into Category 5 tropical cyclones on the Saffir–Simpson scale (SSHWS). This year, for the first time on record, at least one such Category 5 system formed in each tropical cyclone basin: Typhoons Mawar, Saola, and Bolaven in the western Pacific Ocean, Hurricanes Jova and Otis in the eastern Pacific, Hurricane Lee in the Atlantic, Cyclone Mocha in the North Indian Ocean, Cyclone Freddy in the southwest Indian Ocean, Cyclone Ilsa in the Australian region, and Cyclone Kevin in the South Pacific. The accumulated cyclone energy (ACE) index for the 2023, as calculated by Colorado State University (CSU) was 857.4 units, which was above the 1991-2020 mean of 770.2 units.
