The 2015 Atlantic hurricane season was the last of three consecutive below average Atlantic hurricane seasons. It produced twelve tropical cyclones, eleven named storms, four hurricanes, and two major hurricanes. The Accumulated Cyclone Energy (ACE) for the season was 68% of the long-term median value. The hurricane season officially began on June 1, 2015, and ended on November 30, 2015. These dates historically describe the period each year when most tropical cyclones form in the North Atlantic basin. However, the first named storm, Ana, developed on May 8, nearly a month before the official start of the season, the first pre-season cyclone since Beryl in 2012 and the earliest since Ana in 2003. The formation of Ana marked the start of a series of seven consecutive seasons with pre-season activity, spanning from 2015 to 2021. The season concluded with Kate transitioning into an extratropical cyclone on November 11, almost three weeks before the official end.

The brown ocean effect is an observed weather phenomenon involving some tropical cyclones after landfall. Normally, hurricanes and tropical storms lose strength when they make landfall, but when the brown ocean effect is in play, tropical cyclones maintain strength or even intensify over land surfaces. Australia is the most conducive environment for this effect, where such storm systems are called agukabams.