Atlantic Hurricane Seasons
The Atlantic hurricane season is the period in a year when hurricanes usually form in the Atlantic Ocean. Tropical cyclones in the North Atlantic are called hurricanes, tropical storms, or tropical depressions. Worldwide, tropical cyclone activity peaks in late summer, when the difference between temperatures aloft and sea surface temperatures is the greatest. However, each particular basin has its own seasonal patterns. On a worldwide scale, May is the least active month, while September is the most active. In the Northern Atlantic Ocean, a distinct hurricane season occurs from August 15 to November 30, sharply peaking from late August through September. The climatological peak of activity is around September 10 each season. The Northwest Pacific sees tropical cyclones year-round, with a minimum in February and March and a peak in early September. In the North Indian basin, storms are most common from April to December, with peaks in May and November. Tropical disturbances that reach tropical storm intensity are named from a pre-determined list. On average, 10.1 named storms occur each season, with an average of 5.9 becoming hurricanes and 2.5 becoming major hurricanes (Category 3 or greater). The most active season was 2005, during which 28 tropical cyclones formed, of which a record 15 became hurricanes. The least active season was the 1914, with only one known tropical cyclone developing during that year.