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).

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.

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.

This was driven by unusually warm sea surface temperatures, low wind shear, and favorable atmospheric pressure patterns.

It also produced the second-highest accumulated cyclone energy (ACE) in the Atlantic basin, surpassed only by the 1933 season.

Hurricane Stan in October was part of a broader weather system that killed 1,668 people and caused $3.96 billion in damage to eastern Mexico and Central America, with Guatemala hit the hardest.

[2] At the time, Adrian was the fourth earliest tropical cyclone to form in the eastern Pacific since reliable record-keeping began in 1971.

October, in particular, was notably quiet, with the formation of only one tropical depression; only three other seasons, 1989, 1995, and 1996, ended the month without the designation of a named storm.

First, Typhoon Haitang became the strongest storm in the basin this year and caused about $1.1 billion in damages in Taiwan and China in mid July.

Similar to Haitang, Typhoon Longwang made landfall in Taiwan and China at a strong intensity causing damages.

The month's first named storm Cyclone Sally formed on the 7th in the Australian basin, however it dissipated two days later.

The Northwest Pacific basin also had an early start with Tropical Storm Kulap forming near the Caroline Islands.

Harvey formed in the Gulf of Carpentaria before making landfall on Queensland and the Northern Territory while Vivienne caused minor oil and gas disruptions in the Timor Sea.

Adrian formed very early shortly after the season started and took an unusually northeast route towards El Salvador making it the closest hurricane ever to approach the country.

Bret was a short lived storm that made landfall Veracruz in Mexico causing minor damage.

The Western Pacific saw the formation of Typhoons Haitang, Matsa and Tropical Storms Nalgae, Banyan, and Washi and Emong.

Dennis was an early-forming Category 4 hurricane that traveled across the Caribbean and eventually striking Alabama inflicting severe damage and killing at least 70 people.

The North Indian Ocean featured the only non-named storm of the month classified as BOB 02 which was short lived.

The Eastern Pacific featured Hurricanes Fernanda, and Hilary, Tropical Storms Greg, and Irwin along with one depression classified as One-C.

The five storms all stayed away from any landmass however, One-C's remnants dropped moderate rain on Hawaii causing minor damage.

The Western Pacific featured three typhoons named Mawar, Talim, and Nabi and Severe Tropical Storms Sanvu and Ghuchol.

The Atlantic featured Tropical Storms Harvey, Jose, and Lee and Hurricanes Irene and Katrina.

Katrina then struck New Orleans causing a large storm surge leaving the city completely flooded.

The Eastern Pacific featured Hurricanes Jova, Kenneth, Max, and Otis and Tropical storms Lidia and Norma.

The Western Pacific featured some deadly storms mostly being Typhoons Khanun, Damrey, Vicente, and Longwang.

The Atlantic season continued with the formation of Hurricanes Maria, Nate, Ophelia, Philippe, and Rita, and a short lived depression.

Nate stayed at sea however it disturbed some Canadian Navy ships heading to the U.S to help in the aftermath of Hurricane Katrina along with Ophelia which affected much of the Eastern United States as well as parts of Atlantic Canada.

In the North Indian Ocean, Cyclonic Storm Fanoos and BOB 08 formed with Fannos making landfall in Southern India.

Zeta continued into January 2006 which made it the second Atlantic tropical cyclones to span two calendar years (the other being Hurricane Alice in 1954–55).