With top winds reaching 85 miles per hour (140 kph), Jova was about 80 miles (130 km) northwest of the major port city of Manzanillo at 2:00 p.m. PDT (0900 GMT), the U.S. National Hurricane Center (NHC) said.
The Miami-based NHC said the center of Jova crossed the Mexican coast near the town of Chamela in the state of Jalisco on a stretch of land dotted with beaches south of Puerto Vallarta. Mexico has no major oil installations in the Pacific.
Downtown in the popular resort of Puerto Vallarta, people boarded up shops as dark clouds gathered for most of Tuesday.
Jalisco authorities protectively set up some 70 shelters. There were no evacuations in Puerto Vallarta but south of the beach resort, people were brought to safety from the towns of Zihuatlan and Melaque near Barra de Navidad.
Earlier on Tuesday, workers scrambled to fill and stack sandbags to protect the professional beach volleyball courts on Puerto Vallarta's coast, where events from the Panamerican Games are scheduled to be staged later this week.
"Steady weakening is expected after the center crosses the coast," the center said earlier. Puerto Vallarta's last big hurricane was Kenna in 2002, which hit with top winds of 144 mph (230 kph) and flooded streets close to the shore, causing damage that took authorities days to clear.