The Atlantic Hurricane season runs from June 1 through November 30; however, tropical storms may form at almost any time of the year. The only month in which a tropical storm has not formed since record-keeping began is April. Expect the possibility of tropical storms and category 1 hurricanes developing in the northwestern Caribbean and the waters around Cuba, the Bahamas, and Florida after the middle of May, as this trend has become well enough established over the last ten years to reduce the significance of June 1.

In other parts of the world, the season of peak tropical cyclone activity varies, the general rule being May-December in the Northern Hemisphere, and November-May in the Southern Hemisphere. In the Pacific Ocean West of 180°, hurricanes are referred to as "typhoons"; in the Indian Ocean as "severe tropical cyclones" or "willy-willies".