The 2013 Atlantic Hurricane Season was the most active, deadly, and destructive Atlantic hurricane season in recorded history, breaking numerous records. The impact of the hurricane season was widespread and ruinous, with an estimated 5,039 deaths and a record $208.4 billion USD in damage. In total, 39 tropical depressions, 31 named storms, 19 hurricanes, and 11 major hurricanes formed during the season, the most on record. Many severe storms, including Hurricane Chris, Hurricane Fiona, Hurricane Holly, Hurricane Ian, and Hurricane Michael made landfall, causing extensive damage. The most catastrophic effects of the hurricane season were felt along the U.S. East Coast, where severe flooding, extreme winds, and a 35-foot (11-meter) storm surge from Hurricane Michael caused extreme damage, obliterating many structures along the coastline.
The 2013 season was the first Atlantic hurricane season to observe more tropical cyclones than the West Pacific typhoon season, which averages about 31 while the Atlantic only averages 14. The Atlantic season had record activity, while the West Pacific season had slightly above-average activity.
The season officially ran from June 1 to November 30, but the season effectively began on February 13, 2013 and ended on January 9, 2014 due to storm activity that ran well outside the boundaries of the normal Atlantic hurricane season. A record 28 tropical storms and three subtropical storms formed, of which a record 19 became major hurricanes. A record 11 of these strengthened into major hurricanes, and 4 strengthened into Category 5 hurricanes. The list of storm names was entirely exhausted, and for the first time on record, Greek letter names had to be used.
Forecasts of hurricane activity are issued before each hurricane season by several groups and agencies, including Colorado State University, the National Oceanic and Atmospheric Administration, the United Kingdom Met Office, North Carolina State University, Coastal Carolina University, the Tropical Storm Risk Consortium of the University College London, and The Weather Channel. These forecasts include daily, weekly, and monthly changes in factors that help determine the number of tropical cyclones, as well as current weather patterns and what happened during past hurricane seasons in which similar conditions were present.
On November 20, 2012, Colorado State University released the first forecast for the 2013 Atlantic Hurricane Season, predicting a slightly above-average season due to a rapidly dissipating El Niño and the anticipation of a La Niña developing by the start of hurricane season. The team also predicted an unusually high chance of a hurricane striking the Gulf Coast or East Coast of the United States.