The storm soaked beaches on the mainland's Pacific coast before turning toward Baja, California, where the eye was scheduled to collide with the peninsula's southern tip around midday (1800 GMT) Friday. John was downgraded to Category 2 with maximum sustained winds of 105 mph.
Officials were preparing to evacuate 10,000 people in Cabo San Lucas and San Jose del Cabo and at least 5,000 others in La Paz, the capital of the state of Baja California del Sur.
Shelters had been set up in 131 schools and state governor Narciso Agundez said residents who refuse to head for higher ground will be forcibly removed from their homes.
"Where there are areas that are highly vulnerable, we will have to do things forcibly," he said.
Shop owners boarded up windows and hotel workers stripped rooms of light fixtures and furniture, in case plate-glass windows were shattered.
Some tourists were being moved out of low-lying, beachfront hotels to accommodations on higher ground, Agundez said.
A statement released late Thursday by tourism authorities said hotel occupancy rates were only at about 40 to 50 percent, as most visitors had been advised to return home. It said that "most hotels have evacuated all their guests," but state Tourism Secretary Alberto Trevino said visitors had actually been relocated to shelters within their hotels and not to emergency facilities.
"Some hotels have appropriate facilities, ballrooms or rooms that are safer and they are moving their tourists there," Trevino said, adding that only between 7,000 and 8,000 visitors were left in Cabo San Lucas.
Ed Feaser, a tourist from Rancho Santa Margarita, California, was strolling the halls of Hilton Los Cabos Beach and Golf Resort, where officials said they had no plans to evacuate. "I wouldn't go anywhere else," he said.
Asked if he had any concern about the oncoming hurricane, he responded: "No fears."
Police and sailors were moving through shantytowns and squatters' camps near a river Thursday night, telling people to get ready for evacuations.
"I'm leaving because things come and go, but life doesn't," said Maria Guadalupe Perez, a 22-year-old who was washing her belongings outside a hut where she lives in preparation for evacuations.
Churning 210 miles southeast of the tip of Baja California, John was moving northwest at 13 mph. A hurricane warning was issued for the peninsula's southern tip, also home to the resort of San Jose del Cabo.
Residents emptied grocery shelves of food and water, and endured long waits for gasoline. At the airport, hundreds of tourists battled for seats on the few planes heading out of the isolated peninsula. Driving out wasn't much of an alternative — there's only one narrow road, 400 miles long, leading to Tijuana.
Among those hoping to get out was 61-year-old Linda Laport, who was vacationing with family a year after Hurricane Katrina flooded her New Orleans home and claimed her father's life.
"We heard there was a hurricane coming — we were not going to take no chances," she said.
Junichi Hriata, 33, was also sick of hurricanes. The 33-year-old journalist from Tokyo was vacationing in Cancun last year when Hurricane Wilma hit, and he spent a week in a shelter without electricity or showers.
"I'm not going through that experience again," he said. "It was hell."
Officials planned to close the airport here as a precautionary measure late Thursday.
Bill Crowley, a 42-year-old tourist from Lakewood, Colorado, was collecting seashells and swimming in the Pacific with his wife when strong gusts of wind forced even die-hard beachgoers to head for cover. He said he would ride the storm out in his beachfront hotel room.
"There's no other place to go," he said. "I would evacuate the first floor of these hotels, but we're on the third floor, so we should be all right."
On Mexico's mainland coast, there was still a hurricane warning for the bay that is home to the resort of Puerto Vallarta, made famous by the 1964 movie "The Night of the Iguana." But the city escaped the storm's wrath.
"We have more than 4,000 tourists, so obviously some tourist activities were called off as a precaution," said Jose Estrada, Puerto Vallarta's director of tourism. "But it was only a light rain, that wasn't even rain. It was more like drizzle."
The mood was much more urgent in Cabo San Lucas, where Antonio Juarez, a 23-year-old construction worker, was nailing sheets of plywood across the windows of a beachfront condominium Thursday.
"The last one hit us, and hit us hard," he said of Hurricane Ignacio, which blew through the area two years ago. "We've learned how to take precautions."
John wasn't likely to affect the United States — cooler Pacific waters tend to diminish storms before they reach California.
Meanwhile, Hurricane Kristy formed far out to sea, but forecasters said some interaction with John was possible. If that happens, Kristy would likely be absorbed by the larger storm, they said.
Officials name both Atlantic and Pacific hurricanes in alphabetical order.