The North Atlantic hurricane season, which starts on June 1, is forecast to be "extraordinary," with between four and seven hurricanes of Category 3 or higher expected, the US National Oceanic and Atmospheric Administration (NOAA) weather agency said on Thursday.

Category 3 storms pack wind speeds over 178 kilometres an hour and wreak devastating damage on houses, uproot trees and often cut off electricity and water for days or even weeks.

"This season is looking to be an extraordinary one in a number of ways," said Rick Spinrad of the NOAA, which cited warm Atlantic ocean temperatures and La Nina conditions in the Pacific for the expected increase in storms.

It said human-caused climate change was warming oceans and melting ice on land, leading to sea level rises that worsen storm surges.

"The forecast for named storms – hurricanes and major hurricanes – is the highest NOAA has ever issued for the May outlook," Spinrad said. "It only takes one storm to devastate a community."

Oceanic heat in the tropical Atlantic Ocean and Caribbean Sea creates more energy to fuel storms.

Hurricane Ian, which struck Florida in September 2022, caused 152 deaths and losses worth US$112.9 billion. (AFP)