An employee boards up the windows of a store as Hurricane Patricia approaches the Pacific beach resort of Puerto Vallarta, Mexico October 23. 2015. [Photo/Agencies]

US President Barack Obama said the United States was standing by ready to help Mexico.

Local schools closed on Friday and some business owners rushed to board and tape up windows. The Federal Electricity Commission (CFE) said it was carrying out electricity shutdowns in the states of Colima, Jalisco and Nayarit.

Traffic stretched way out of Puerto Vallarta en route to Guadalajara, which is Mexico's second-biggest city and around a 5-hour drive inland.

The strongest storm ever recorded was Cyclone Tip which hit Japan in 1979.