The 2011 Atlantic hurricane season was the second in a group of three very active Atlantic hurricane seasons, each with 19 named storms, only behind 1887, 1995, 2010, and 2012. The above-average activity was mostly due to a La Niña that persisted during the previous year. Of the season's 19 tropical storms, only seven strengthened into hurricanes, and four of those became major hurricanes: Irene, Katia, Ophelia, and Rina. The season officially began on June 1 and ended on November 30, dates which conventionally delimit the period during each year in which most tropical cyclones develop in the Atlantic Ocean. However, the first tropical storm of the season, Arlene, did not develop until nearly a month later. The final system, Tropical Storm Sean, dissipated over the open Atlantic on November 11.

The 2010 Atlantic hurricane season was the first of three consecutive very active Atlantic hurricane seasons, each with 19 named storms. This above average activity included 12 hurricanes, equaling the number that formed in 1969. Only the 2020 and 2005 seasons have had more, at 14 and 15 hurricanes respectively. Despite the high number of hurricanes, not one hurricane hit the United States making the season the only season with 10 or more hurricanes without a United States landfall. The overall tropical cyclone count in the Atlantic exceeded that in the West Pacific for only the second time on record. The season officially began on June 1 and ended on November 30, dates that conventionally delimit the period during each year when tropical cyclone formation is most likely. The first cyclone, Alex intensified into the first June hurricane since Allison in 1995. The month of September featured eight named storms. October featured five hurricanes, including Tomas, which became the latest on record in a calendar year to move through the Windward Islands. Activity was represented with an accumulated cyclone energy (ACE) value of 165 units, which was the eleventh highest value on record at the time. The activity in 2010 was heightened due to a very strong La Niña, which also led to an inactive Pacific hurricane season.