If you think it's colder than usual, it's not your imagination.
Downtown Sacramento matched a record low for Sunday, dropping to 27 degrees at 6:24 a.m. That matched the record for Jan. 13 from 2007, said National Weather Service forecaster Karl Swanberg.
And while it's expected to remain cold into this morning, Swanberg noted, "we've got a tough record to break" for today. The record low for Jan. 14 is 19 degrees, all the way back in 1888.
Still, the National Weather Service reported that a hard freeze warning has been issued for this morning for the Central Valley from Redding south to Modesto, meaning that lows are equal to or below 28 degrees for at least three hours. NWS forecaster Drew Peterson said the temperatures will warm slightly each day as the week progresses.
That's nothing if you live in Chester, Burney, Alturas or South Lake Tahoe. Peterson said temps fell to 8 below zero in Burney overnight and 7 below in Chester. It was 21 below in Alturas way up in Modoc County and 14 below at the South Lake Tahoe airport.
"We have a weather spotter in Burney, and he said it's the coldest it has been in 25 years," Peterson said.
There are plenty of reasons for the icy temperatures.
The valleys tend to feel more of the cold than the foothills, Peterson said, since the cold rolls down mountainsides and hangs around the valley floor.
Added to that is the lack of a cloud cover, allowing any warm air to escape into the atmosphere. It also tends to be colder where there's not much air movement, Peterson said. That's why it often seems colder in rural areas than, say, downtown Sacramento.
The backdrop to all this is the extremely cold air coming through the Pacific Northwest from Canada, resulting in what the weather mavens call an "amplified high-pressure ridge off the coast." That has produced much of the cold near the coasts of California, Oregon and Nevada.
Those low-low readings in Burney and Chester are particularly cold because of their geography. Burney is at the base of Burney Mountain some 50 miles east of Redding. Chester is in the Lake Almanor basin.