GENEVA -Hurricane Beryl, which has strengthened to a Category 5 storm, is setting the tone for a "very dangerous" hurricane season, the World Meteorological Organization said on Tuesday.

Beryl swept through Grenada and St Vincent and the Grenadines, leaving many households without power, and is expected to hit Jamaica on Wednesday and the Cayman Islands later in the week.

"It's the earliest Category 5 hurricane on record in the Atlantic, Caribbean and Central American basin," WMO spokesperson Clare Nullis told reporters in Geneva.

"It sets a precedent for what we fear is going to be a very, very, very active, very dangerous hurricane season, which will impact the entire basin."

A Category 5 hurricane under the five-step Saffir-Simpson Hurricane Wind Scale brings winds of 252 kilometers an hour (157 miles per hour) or higher, capable of causing catastrophic damage including the destruction of homes and infrastructure.

"We need to bear in mind that it only takes one land-falling hurricane to set back decades of development," Nullis said.

"We fear what is happening with Hurricane Beryl, which has hit very, very small islands in the Caribbean that are not used to this size of hurricane."

Anne-Claire Fontaine, scientific officer for the WMO Tropical Cyclone Programme, said one reason for Beryl developing so early in the season was linked to warmer ocean temperatures.

"The Main Development Region (MDR), the place in the ocean where the hurricanes are developing... is the warmest ever."

  - Reuters