The 2017 Atlantic hurricane season was a devastating and extremely active Atlantic hurricane season that became the costliest tropical cyclone season on record worldwide, with a damage total of at least $294.92 billion (USD). It was the second consecutive above–average season dating back to 2016. The season featured 17 named storms, 10 hurricanes, and 6 major hurricanes. Most of the season's damage was due to hurricanes Harvey, Irma, and Maria. Another notable hurricane, Nate, was the worst natural disaster in Costa Rican history. These four storm names were retired following the season due to the number of deaths and amount of damage they caused. Collectively, the tropical cyclones were responsible for at least 3,364 deaths. The season also had one of the highest accumulated cyclone energy (ACE) on record, with an index of 225 units. A record three hurricanes generated an ACE of over 40: Irma, Jose, and Maria. This season featured two Category 5 hurricanes, and the only season other than 2007 with two hurricanes making landfall at that intensity.