Parts of Mexico are at risk of major floods and landslides after Hurricane Patricia, the strongest storm recorded in the Americas, made landfall.
The storm touched down in western Mexico, bringing destructive winds and rain, but heavy damage appears to have been avoided.
The US National Hurricane Center said the hurricane hit as a Category Five storm - the highest classification.
It said "life-threatening flash floods and mudslides" were now likely.
The states of Nayarit, Jalisco, Colima, Michoacan, and Guerrero are in particular danger as the storm moves inland, the centre says.
Four hours after making landfall as the strongest recorded hurricane, Patricia weakened to a
Category Four, and is likely to be downgraded to a tropical storm in the coming hours as it passes over mountainous regions.
"The first reports confirm that the damage has been smaller than that corresponding to a hurricane of this magnitude," Mexico's president, Enrique Pena Nieto, said in a televised address.
Mexican federal police said only "minor landslides and fallen trees" had so far been reported in Colima.
But the government has warned that ash from the Colima volcano, which has become increasingly active this year, could combine with heavy rainfall to trigger huge mudflows.
Some 400,000 people live in vulnerable areas, according to Mexico's National Disaster Fund.
Patricia reached land in the Cuixmala area of the western Jalisco state, some 85km (55 miles) from the port city of Manzanillo.
The US National Hurricane Center said Patricia hit the coast with winds of 265km/h (165mph), making it the most powerful storm ever to be recorded in the Americas.
At one point before landfall, the hurricane's winds had been strong enough "to get a plane in the air and keep it flying", World Meteorological Organisation spokeswoman Claire Nullis said.
Video filmed in the port city of Manzanillo shortly before the hurricane struck showed trees bending in severe wind.
While sheltering with his family in Manzanillo, Jacob Lozano Salazar told the BBC: "We're all safe but it's really ugly here on the coast."
Residents had stocked up on food and other supplies, while shop owners boarded up windows.
Jalisco is home to the resort town of Puerto Vallarta, which appeared to have escaped the worst of the storm.
Police patrols in the resort urged people to leave the shorefront for safer areas at least three blocks inland, while loudspeakers ordered hotel residents to evacuate.
The town's airport, along with two others in the path of the storm, were closed.
