Hurricane Ernesto was the costliest tropical cyclone of the 2006 Atlantic hurricane season. The sixth tropical storm and first hurricane of the season, Ernesto developed from a tropical wave on August 24 in the eastern Caribbean Sea. Ernesto first affected the northern Caribbean, reaching minimal hurricane status near Haiti before weakening and moving across eastern Cuba as a tropical storm. Despite initial predictions for it to track through the eastern Gulf of Mexico as a major hurricane, Ernesto moved across eastern Florida as a weak tropical storm. After turning to the northeast, it re-intensified and made landfall on August 31 on the North Carolina coast just below hurricane status. Late the next day, Ernesto became extratropical after entering southern Virginia. The remnants spread moisture across the northeastern United States before dissipating over eastern Canada on September 4.

The 2006 Atlantic hurricane season was the least active in the basin since 1997, with nine named storms as well as an additional unnamed tropical storm identified by the National Hurricane Center. 2006 was the first season since 2001 in which no hurricanes made landfall in the United States, and was the first since 1994 in which no tropical cyclones formed during October. Following the intense activity of 2003, 2004, and 2005, forecasters predicted that the 2006 season would be only slightly less active. Instead, it turned out to be a below average season, as activity was slowed by a rapidly forming moderate El Niño event, the presence of the Saharan Air Layer over the tropical Atlantic, and the steady presence of a robust secondary high-pressure area to the Azores High centered on Bermuda. There were no tropical cyclones after October 2.