It's expected to get close to the freezing mark Tuesday night in some parts of the Bay Area.
They're turning on the heat everywhere, including the Oakland Zoo where the water for Roosevelt, the alligator, is being kept at a cozy 75 degrees. And O.J., the 130-year-old Aldabra tortoise, is taking cover in a barn with heat lamps.
"With the frost warning coming, we definitely want them locked in. And you can see we added a little extra hay tonight so they stay nice and cozy," said Oakland zookeeper Shana Jensen.
Meantime, others are rushing to dive into this cold weather. There was a line of customers at the Any Mountain store in Berkeley, who want their skis tuned up for the slopes.
Sierra ski resorts including Heavenly and North Star are now open with half-a-foot of new snowfall. Other resorts are deciding if they should open this Saturday -- a week early.
If you're headed to Tahoe, the guys at Dan Chin's Auto Shop remind you that cold air drains the charge in your battery faster and reduces the pressure in your tires. So check your tire pressure, battery and also your anti-freeze. It's all part of the change in habits that comes with this change in temperatures.
Earlier on Tuesday, Diablo Solar Services checked on their customers. They have about 25,000 customers who use water insulated solar panels to heat their swimming pools.
"The water in the panels, when it gets down to 24, 25 degrees, they will freeze and the tubes in the panels split open," said Daryl Sobolik of Diablo Solar Services.
For people who have plants like citrus or bougainvillea, they might want to buy some protective spray or a microfiber blanket from a nursery.
"Well, frost can occur at temperatures above freezing, despite the fact that we haven't had an actual 32 degree mark. So, sometimes frost can settle on plants even when it's 33, 34, 35 out," said Steven Wexler of Navlet's Garden Center.
The Orchard Supply Hardware store in Livermore has stocked up on space heaters, from inexpensive to fancy. Firewood is also a big seller.
Contra Costa County Supervisor John Gioia is collecting new coats for children who don't own coats. Specifically, for all 365 students at a low-income elementary school in Richmond.
"When we're out there, we see many of these children without coats and especially in this cold weather, it makes you understand the importance of being properly clothed so you're ready to learn," said Gioia.
Gioia has organized the coat drive for five years this year they are nearly 200 coats short of their goal.
In San Rafael, the cold weather has arrived. The North Bay is expected to see temperatures dip Tuesday night. Carry Knight of Mill Valley made a special trip to Nero's Firewood in Novato to stock up for the cold days ahead.
"We usually buy a full cord but we can't wait to get the whole cord so I'm just filling up my back seat," she said.
Business at Nero's had been slow until Tuesday.
"Usually rain is what drives the sales but this week with the anticipated weather; it's perked up today and it should be good throughout the week," said Dave Skavland of Nero's Firewood.
Michael Kernan wasn't selling too many Christmas trees Tuesday morning, but was busy working to keep warm.
"You've got to wear a few more layers out here. You know, put on some thermals and extra jackets, sweatshirt," said Kernan of 3 Kings Trees.
On the bright side, this cold weather is great for his trees.
The low temperatures expected Tuesday night were of great concern to the homeless population of San Rafael. St. Vincent de Paul Society of Marin County was ready to provide shelter to 40 men and 20 women.
"Each night they will be taken to a different congregation in Marin. We have 19 host congregations. Our guests will sleep on the floor and have a dinner and be protected from the elements," said Christine Paquette of St. Vincent de Paul Society of Marin County.
Because of the freezing temperatures, they expect a full house.