The 2004 Atlantic hurricane season was a very deadly, destructive, and active Atlantic hurricane season, with over 3,200 deaths and more than $61 billion in damage. More than half of the 16 tropical cyclones brushed or struck the United States. Due to the development of a Modoki El Niño – a rare type of El Niño in which unfavorable conditions are produced over the eastern Pacific instead of the Atlantic basin due to warmer sea surface temperatures farther west along the equatorial Pacific – activity was above average. The season officially began on June 1 and ended on November 30, though the season's last storm, Otto, dissipated on December 3, extending the season beyond its traditional boundaries. The first storm, Alex, developed offshore of the Southeastern United States on July 31, one of the latest dates on record to see the formation of the first system in an Atlantic hurricane season. It brushed the Carolinas and the Mid-Atlantic, causing one death and $7.5 million (2004 USD) in damage. Several storms caused only minor damage, including tropical storms Bonnie, Earl, Hermine, and Matthew. In addition, hurricanes Danielle, Karl, and Lisa, Tropical Depression Ten, Subtropical Storm Nicole and Tropical Storm Otto had no effect on land while tropical cyclones. The season was the first to exceed 200 units in accumulated cyclone energy (ACE) since 1995, mostly from Hurricane Ivan, the storm produced the highest ACE. Ivan generated the second-highest ACE in the Atlantic, only behind 1899 San Ciriaco Hurricane.

Hurricane Alex was one of the northernmost major hurricanes on record, and whose formation marked the fifth-latest start to an Atlantic hurricane season since 1952. The first named storm, hurricane, and major hurricane of the 2004 Atlantic hurricane season, Alex developed from the interaction between an upper-level low and a weak surface trough on July 31 to the east of Jacksonville, Florida. It moved northeastward, and strengthened to attain winds of 100 mph (160 km/h) before passing within 10 miles (16 km) of the Outer Banks coast. Alex strengthened further and reached a peak of 120 mph (190 km/h) winds while off the coast of New England, one of only six hurricanes to reach Category 3 status north of 38° N. Alex caused a scare of a hurricane-force direct hit in the Outer Banks of North Carolina, which had been devastated by Hurricane Isabel less than a year earlier.