Hurricane Joseph was the most destructive hurricane of the 2015 Atlantic Hurricane season, as well as the deadliest hurricane in the Atlantic basin in recorded history, the deadliest and costliest natural disaster in U.S. history (and one of the most devastating natural disasters in world history), and the most intense tropical cyclone on record. The hurricane was also considered to be the strongest tropical cyclone in world history, with sustained winds exceeding 250 mph (400 km/h), a wind speed that is only seen in tornadoes. Hurricane Joseph was the first tropical cyclone to be rated a category 7. It was rated by the National Hurricane Center to help emphasize the need to evacuate in areas that would suffer in the hurricane.