Tropical cyclones in 2005

The activity was the most active Atlantic hurricane season in recorded history at the time, shattering numerous records, with 31 tropical or subtropical cyclones recorded. The United States National Hurricane Center[nb 1] named 27 storms, exhausting the annual pre-designated list and resulting in the usage of six Greek letter names. A record 15 storms attained hurricane status, with maximum sustained winds of at least 74 mph (119 km/h); of those, a record seven became major hurricanes, which are a Category 3 or higher on the Saffir-Simpson scale. The season's impact was widespread and catastrophic. Its storms caused an estimated 3,912 deaths and approximately $171.7 billion in damage. It was the costliest season on record at the time, until its record was surpassed 12 years later. It also produced the second-highest accumulated cyclone energy (ACE) in the Atlantic basin, surpassed only by the 1933 season. The season officially began on June 1, 2005, and the first storm – Arlene – developed on June 8. Hurricane Dennis in July inflicted heavy damage to Cuba. 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. The final storm – Zeta – formed in late December and lasted until January 6, 2006.

On the Eastern and Central Pacific, three simultaneous tropical cyclones existed on September 22. Jova, Kenneth and Max

The activity continued the trend of generally below-average activity that began a decade prior. The season's first tropical cyclone, Adrian, developed on May 17 and reached its peak as a Category 1 hurricane. Named storms are infrequent in May, with one tropical storm every two years and a hurricane once every four years.[2] At the time, Adrian was the fourth earliest tropical cyclone to form in the eastern Pacific since reliable record-keeping began in 1971. Activity throughout the remainder of the season was far less notable, with 16 tropical cyclones, 15 named storms, 7 hurricanes, and 2 major hurricanes. The long-term 1971–2004 average suggests an average season to feature 15 named storms, 9 hurricanes, and 4 major hurricanes. 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.[3]

Although the season was quiet, some typhoons caused extensive damages in many places, especially in China where eight typhoons struck the country. 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. In August, Typhoon Matsa made landfall in Eastern China and caused about $2.23 billion in damages. Later that same month, two powerful typhoons made landfall, causing extreme damage and some casualties. Similar to Haitang, Typhoon Longwang made landfall in Taiwan and China at a strong intensity causing damages. The season also marked the first time the Atlantic hurricane season was more active than the Pacific typhoon season (the others being 2010 and 2020). However, the 2005 Atlantic hurricane season featured record high activity while the Pacific typhoon season featured near average activity.

There were a total of 12 depressions during the year, three less than normal, although the highest since 1992. The IMD named four cyclonic storms, a process they initiated in 2004, which was also below normal. No systems strengthened beyond cyclonic storm status. The season was the sixth in a row with below normal activity, based on the seasonal accumulated cyclone energy. Storms generally develop when the monsoon trough is located over tropical waters, with a peak from May to June and another peak in November.[4] The monsoon developed 11 distinct low pressure areas by the end of September, including five monsoon depressions,[5] and the monsoon season was more active than usual.