Pope John Paul II, in a Christmas Day address spoken in 52 languages from Vatican City, urged mankind not to be tempted to see salvation in technology and to look instead to the message of Christ's birth.

About 50,000 pilgrims stood under gray skies in St. Peter's Square and millions more people in at least 34 countries were able to watch the pope live on television as he proclaimed his message "Urbi et Orbi" -- to the city and the world.

In the United States, the desert city of Tucson enjoyed its first white Christmas on record, while seaside San Diego reported its first snow flurries in 20 years.

Some children in Ormond Beach, Fla., threw snowballs and built a snowman next to their pool yesterday, thanks to an uncle from Illinois who hauled nearly 800 pounds of snow by pickup truck so his nephews and nieces could see it for the first time.

At the White House, President Reagan and his wife, Nancy, talked with all their children by telephone Christmas morning. They planned to eat a traditional turkey dinner with 21 guests.

It was a time for other traditions, too. In New York, admirers of Irving Berlin serenaded the 99-year-old composer of "White Christmas" at his Manhattan home on Christmas Eve. And bonfires burned along the levees upriver from New Orleans; tradition says they light the way for Pere Noel, the Cajun version of Santa Claus, as he paddles his gift-laden pirogue downriver.

Animal-rights activists delivered such exotic fruits as mangoes, kiwis and coconuts to apes and monkeys at the National Zoo here. Afterward, they stood in the rain outside the zoo gates and sang animal-oriented Christmas carols.

For hundreds of newly enlisted seamen stationed in the Chicago area, Christmas was dinner sponsored by the USO in a downtown hotel and free phone calls home.

"Chicago's a lot different than a small town, but the Christmas spirit in the downtown area is a lot better than I expected," said Gary Carlson, 18, who was away from his family in the tiny Iowa town of Tama for the first time.

The turkey, potatoes and peas were "better than the chow in the Navy," said Todd Eifert from Lakehurst, N.J.

"But nothing's as good as Mom's," said Garth Schoffman, 18, from Akron, Ohio.

In Boston, where more than 2,000 people were expected to sit down to donated holiday meals, the privately run Pine Street Inn said it had received donations of hundreds of flowers as well as food.

"The place is decorated like a flower shop," said Mark Baker, an inn spokesman. "It's just beautiful."

At Rosie's Place shelter in Boston, which accepts women and children, Santa Claus visited some of the 80 women and 20 children gathered for brunch.

"There's someone playing the piano, and some are singing," said volunteer Kate O'Brien.

Volunteer firefighters in Killingly, Conn., rounded up presents for a family of five who were burned out of their home on Christmas Eve.

"It's Christmas, and it's what you have to do to help your neighbor," said Darius Hopkins, chief of the East Killingly Volunteer Fire Company.

Los Angeles Mayor Tom Bradley welcomed three homeless families on Christmas Eve to the first of 102 city-purchased mobile homes meant to provide temporary housing. And National Guard armories across southern California opened because of cold weather to provide shelter for the homeless.

A group of 23 Swiss and German tourists in Los Angeles were relieved when their missing tour bus, carrying their luggage, money and passports, turned up on a downtown street. The woman who drove the bus stranded the visitors at a movie studio; the organization sponsoring the tour bought the visitors clothing and put them up in a hotel overnight.

The giving began Christmas Eve in the San Fernando Valley in southern California when officers in police cruisers, with lights flashing, delivered Christmas gifts to needy children.

"It's the best Christmas because someone gave us toys and gifts," said Manuel Loza, 10, who lives with six siblings and other family members in a converted garage.

In Fall City, Wash., Dmitri Vinogredov, a 30-year-old Soviet zoologist who was granted asylum last August, said living in the United States is enough of a Christmas present.

"Freedom is the biggest treasure. After I got it, I have no big dreams," he said.