The 2008 Atlantic hurricane season was the most destructive Atlantic hurricane season since 2005, causing over 1,000 deaths and nearly $50 billion in damage. The season ranked as the third costliest ever at the time, but has since fallen to ninth costliest. It was an above-average season, featuring sixteen named storms, eight of which became hurricanes, and five which further became major hurricanes. It officially started on June 1 and ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin. However, the formation of Tropical Storm Arthur caused the season to start one day early. It was the only year on record in which a major hurricane existed in every month from July through November in the North Atlantic. Bertha became the longest-lived July tropical cyclone on record for the basin, the first of several long-lived systems during 2008.

A tropical cyclone is a rapidly rotating storm system with a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its location and strength, a tropical cyclone is called a hurricane, typhoon, tropical storm, cyclonic storm, tropical depression, or simply cyclone. A hurricane is a strong tropical cyclone that occurs in the Atlantic Ocean or northeastern Pacific Ocean, and a typhoon occurs in the northwestern Pacific Ocean. In the Indian Ocean and South Pacific, comparable storms are referred to as "tropical cyclones". In modern times, on average around 80 to 90 named tropical cyclones form each year around the world, over half of which develop hurricane-force winds of 65 kn or more. Tropical cyclones carry heat away from the tropics and transport it towards temperate latitudes. This plays an important role in regulating global climate. Tropical cyclones can be very harmful for people.