Tropical cyclones in 2005

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 (seven basins combined), as calculated by Colorado State University was 899.6 units.

The deadliest tropical cyclone of the year was Hurricane Stan in the North Atlantic Ocean, which killed more than 1,600 people in Central America, while the costliest tropical cyclone was Hurricane Katrina – also in the North Atlantic Ocean – which caused more than $125 billion in damage after striking United States especially New Orleans and its surrounding areas, making it the costliest tropical cyclone on record, tying with Hurricane Harvey in 2017.