It's unusal for Sacramento to get this cold in early December with a chance of measurable snow. So, why it that?

Turns out this cold is just a freak of nature, literally.

"One of the main reasons that we get colder than normal weather for interior California is when we get air that comes down from Canada," Brooke Bingaman with the National Weather Service said. 

Bingaman says typically winter storms in Sacramento come from over the ocean and they're warmer and normally produce just rain.

She also says that's why the forecasted combination of extreme cold leading to snowfall in Sacramento is so rare.