(Wines&Vines) - With bud break occurring in vineyards throughout California, it appears 2015 could be another early vintage and one that hopefully is not marked by frost.

Bud break has now been reported from all of California’s key wine grape regions from Temecula Valley in the south to Mendocino County in the north. Growers in Mendocino County have already had to turn on wind machines or sprinklers to protect emerging buds from temperatures that dipped into the low 30°s.

It’s not uncommon for overnight lows to reach into the 30°s or lower in California. In 2008, a series of frosts limited yields throughout much of the state, and a lengthy stretch of freezing temperatures in late April severely reduced the 2011 crop in Central Coast growing areas.

“We thought last year was early,” said Steve Andrews, owner of Oak Mountain Winery in the Temecula Valley, who said he’s seeing buds pushing in his hillside vineyards.

North Coast

A few nights of below-freezing temperatures in Mendocino County already have done some damage, said Joe Webb, owner and winemaker of Foursight Wines in Boonville, Calif., and the current president of the Anderson Valley Winegrowers Association.

Webb said he knows of one vineyard near Philo, Calif., where the owner opted not to frost protect because less than 1% of vines where showing growth. Unfortunately, what was showing was fried. Webb said he just completed double-pruning Foursight’s 15 acres of estate vineyards and expects to make the final pruning in mid-March. He said last year was about two weeks early, on average, and this year it looks more like three. Vineyards set to canes are about three to four weeks early.

He said he installed a wind machine last year as well as a Davis Instruments Vantage Pro2 weather station. Data from the weather station, as well as from others in the county, is sent to the private weather firm Fox Weather in Fortuna, Calif., which provides frost forecasts for Mendocino County and other regions in California.

Better data ensures more accurate forecasts, so Webb knows when to turn on the wind machine or just wait for temperatures to drop to 32° F or colder and turn on the sprinklers. “We’d rather not have the noise and burn the propane if we don’t have to,” he said of the wind machines.