A state of emergency was declared in three Mexican states on Friday, as Hurricane Patricia approached the Pacific coast.
Originally designated a tropical storm, within 24 hours Patricia had become a category five hurricane, and was expected to make landfall on Friday afternoon or evening.
According to the US National Hurricane Center, "potentially catastrophic" Patricia is "the strongest hurricane on record" in the eastern Pacific or the Atlantic.
Schools and airports were closed in Jalisco, home to the resort town of Puerto Vallarta, Colima and Guerrero states, while locals and tourists were evacuated from the coastal regions, and as residents awaited fierce winds of 325km/h (200mph).
Around 400,000 people live in vulnerable areas in Hurricane Patricia's path, said Mexico's National Disaster Fund.
Authorities have warned of potential flooding from the sea and destructive waves on the coast, as well as torrential rain, flash floods and mudslides throughout the affected regions.
The World Meteorological Organization compared Patricia's intensity to Typhoon Haiyan, which killed more than 6,000 people in the Philippines when it hit in 2013.