It's going to get really cold overnight. In fact, you'll want to bring your pets indoors...and you may want to cover your outdoor water pipes. 

"We have a freeze warning in effect for the Sacramento Valley tonight. Could have maybe three to four hours where temperatures drop down in the middle to upper 20s."

Steve Goldstein is a meteorologist with the National Weather Service office in Sacramento.

"We issue hard freeze warnings or freeze warnings when we have temperatures drop down into the mid-20s. That's a little unusual for Sacramento to be that chilly. So that's our freeze warning criteria."

Goldstein says a cold, dry air mass over the region combined with clear skies and light winds will allow temperatures to rapidly cool. This is the first "freeze warning" of the season. It'll be in effect from midnight through 9 AM Tuesday.

Officials with the California Emergency Management Agency are urging people to prepare for the severe cold.