As California gets a break this weekend from months of serial rainstorms, unusually cold temperatures are descending over the state’s famed wine country. 

As Greta Mart from member station KRCB reports, grape growers are concerned the frost could damage their crops.

Just as new buds have begun to sprout on the grape vines in Sonoma County, the National Weather Service has issued a frost advisory through early Sunday morning.

The chilly temperatures come at a dangerous time for grapes.

Jack Sporer, who owns vineyards, was out checking enormous fans Friday that help stave off the frost.

"Frost is an issue for vines after they've had bud break," Sporer said. "If you get a frost after the green flesh material emerges from the woody canes, that can freeze off and die, and you'll lose an entire crop for a year, potentially."

It's difficult to predict which vineyards will be hit with frost because of the region's many microclimates.

For NPR News, I'm Greta Mart in Sonoma County.