If it seems as though it's colder than usual for a January in the Central Valley, that's because it's colder than usual for a January in the Central Valley.
"Basically, we're under a drier weather pattern with less clouds, so we are able to cool off more overnight," said Stefany Henry, a meteorologist with the National Weather Service. "Another reason is we're stuck under this northerly wind flow, so we're getting a lot of cold air channeling down into the area."
That air is coming from the Alaska region, and a high-pressure system to the west is keeping it here, Henry said. Temperatures are several degrees lower than a typical early January.
The moisture in the air makes for frosty conditions come sunup; Friday morning saw drivers scraping windshields and children huddled under hoods as they headed to school.
The next few days look as though there will be more of the same, with highs in the 40s and lows in the 20s and 30s. There may be some snow in the higher elevations this weekend, but there's no precipitation headed to the valley.
Southern California is experiencing the same kind of weather conditions. Snow over the Grapevine section of Interstate 5 has led authorities to close the key artery linking Southern and Northern California several times this week.
The cold weather affects the four-legged among us, as well, and dog and cat owners are reminded to bring pets inside. Sustained below-freezing conditions could lead to frozen pipes or damage to fragile plants.
Citrus growers in the southern part of the Central Valley were taking action to protect their crops, but most farmers in the Modesto area had nothing to fear.
"Actually, this is beautiful," said Roger Duncan, Stanislaus County farm adviser for the University of California Cooperative Extension. "Tree crops need cold in order to break their rest."
He said years with warm winters are more harmful than cold snaps such as the one we're experiencing.
"The trees have to have a certain amount of cold in order to bloom and have their maximum crop potential," Duncan said.
He said temperatures would have to dip into the low 20s or teens to do any real damage.
"I don't expect we would have any problems with it," he said. "If this happens two months from now, we'll be concerned. In December and January, it's a good thing."
Breaking News Editor Patty Guerra can be reached at firstname.lastname@example.org or (209) 578-2343. Follow her on Twitter, @pattyguerra.