It's so cold outside that Daniel Weaver put on extra thick moisturizer "so my face doesn't freeze off" before he rode his bike to work Thursday morning in San Jose. "Chuy," the miniature pincer Pomeranian pup he carries to work in his backpack each day, barely poked his head out.

It's so cold that across the Bay Area -- down to 16 degrees in Napa Thursday and 18 degrees in Morgan Hill -- water lines burst and black ice caused spinouts. Planes at San Jose and Oakland needed de-icing, golfers in Livermore waited out frost delays and the tortoises at the Oakland Zoo were surprised by a thin layer of ice on their pool.

A worker walks through a wine vineyard on a cold day in Livermore, Calif., on Thursday, Dec. 5, 2013. The weekend forecast calls for low temperatures
A worker walks through a wine vineyard on a cold day in Livermore, Calif., on Thursday, Dec. 5, 2013. The weekend forecast calls for low temperatures throughout the Bay Area. Mountain peaks above 2,000 feet like Mt. Diablo and Mt. Hamilton may get a dusting of snow. (Doug Duran/Bay Area News Group) ( Doug Duran/Bay Area News Groug )

It's so cold that security guard Anthony Garcia, in double socks and winter gloves, overlooked the homeless people taking shelter inside the Diridon Caltrain station in downtown San Jose. "I just left them alone,'' he said.

It hadn't ever been this cold on this date in Oakland since they started keeping track: downtown broke a 1972 record when it plunged to 34 degrees early Thursday. San Jose tied a 41-year-old record at 29 degrees overnight, and San Francisco did the same at 40 degrees. Livermore plummeted to 24, Concord dropped to 25 and Redwood City dipped to 27.

"My teeth are cold," said Danielle Garvey, 37, who lives in the Santa Cruz Mountains.

It's so cold that the water bottles froze solid for the rabbits at the Sulphur Creek Nature Center in Hayward and Rose Britton, the director of animal care, had to wake up the bats for breakfast who were snuggling in their netting-enclosed reptariums.

"There's frost everywhere and the volunteers don't want to go out there," Britton said from her office in the Hayward Hills. "I have a lot of retired people. They're not too happy about this cold weather. We all have jackets and mittens and caps."

Keep them close. While it is warming up during the day, freezing overnight temperatures are expected to stick around through the weekend. On Friday, rain is expected to turn to snow on the mountaintops at about 2,000 feet and raise temperatures slightly through Saturday afternoon. But break out the mittens again overnight Saturday and into Sunday morning when a deep chill will set in again.

Overnight temperatures in the teens and 20s might seem balmy to the folks in Great Falls, Mont., where temperatures dipped to 12 degrees below zero Thursday. But, hey, we're sharing similar temperatures with Chicago and Erie, Penn., for crying out loud. Even Toronto was warmer on Thursday -- 55 degrees overnight!

Not that that gives us a right to complain. But still.

"We're not prepared for temperatures that go down this low for any length of time," said meteorologist Diana Henderson at the National Weather Service, which issued a freeze warning for parts of the Bay Area. "It takes its toll."

For people, plants and animals used to California's Mediterranean climate, it stings.

And it's no fun when you go to turn on the shower and nothing comes out.

"I had a call this morning where a lady had her solar thermal system and she thought her water heater went out," said Ron Burris from the Concord office of Benjamin Franklin Plumbing. "We went out there and found out her solar water pipes had frozen. She didn't have any water -- no hot, no cold, no nothing. Same thing with another customer. The pipes were frozen."

Sometimes, it just takes a little sunshine for them to thaw out. "By midmorning they're calling to cancel because they unfroze," said Kim Barrios, a plumbing dispatcher in Novato.

The California Highway Patrol spread salt on the roadways after one car spun out on black ice on northbound Interstate 280 near Highway 92 early Thursday and traffic slowed in Walnut Creek after a big patch of it developed on Ygnacio Valley Road at Oakland Boulevard, near the Interstate 680 on ramps.

It was cold in Los Gatos, too, down to the 20s. But that didn't stop Jessica Helbush, 28, from waiting outside Wednesday night, shivering, for her first date with Alex Hanway. She had given him the wrong directions in the first place and was worried he might not find the right restaurant.

"He just seems like a really nice person. I definitely had to wait outside," she said, "or that would just be mean."

Staff Writer Rick Hurd contributed. Contact Julia Prodis Sulek at 408-278-3409. Follow her at Twitter.com/juliasulek.

HOW LOW DID THURSDAY temps GO?
Oakland: 34-#
San Jose: 29#
San Francisco: 40#
Livermore: 24
Concord: 25
Redwood City: 27
Morgan Hill: 18
Napa: 16
#--Broke or tied record low for Dec. 5.
Source: National Weather Service