But the U.S. National Hurricane Center in Miami predicted that Emily would strengthen again as the storm picks up moisture over the warm waters of the steamy Gulf of Mexico.
Emily is forecast to menace northern Mexico's Gulf coast and the southern tip of Texas by Wednesday and could affect the entire northern half of Mexico on Thursday.
A total of 15,800 oil platform workers in the Gulf of Mexico were said to have been evacuated. A pilot and co-pilot were killed Saturday when their helicopter crashed into the sea while evacuating workers from a state-owned Petroleos Mexicanos oil platform.
Earlier this month, disruption of Gulf oil drilling by Hurricane Dennis caused a temporary spike in oil prices on the New York Mercantile Exchange.
Emily hit the Yucatan Peninsula early Monday with winds measured at up to 215 kilometres per hour. Huge waves were causing flooding in some areas and power supply was disrupted as thousands of people, including tourists, sheltered in schools and other protected buildings.
Tens of thousands of people had been evacuated from tourist resorts including Cancun, Cozumel, Playa del Carmen and Tulum along nearly 200 kilometres of the east-facing Yucatan coastline.
But no deaths or major damages have been reported so far in the area.
"We hope that it stays like that," Carmen Segura, the head of Mexico's civil defence force, said.
By late Sunday, seven deaths had been reported in the Caribbean from Emily's rampage - one in Grenada, four in Jamaica and two in Mexico.
A week earlier, Hurricane Dennis had caused major damage to parts of Haiti and much of Cuba, plus localized flooding in the Florida Panhandle and southern Alabama.
This year marks the first time since records have been kept that there have been five named storms this early in the season. Last year's hurricane season was one of the worst on record in terms of destruction, blowing four devastating storms through the Caribbean and across Florida. dpa ff amh pr
- Deutsche Presse Agentur
- Copyright (c) dpa Deutsche Presse-Agentur GmbH