Ranchers in West Marin are buying expensive hay and selling off portions of their herd in the wake of the driest year on record in Marin, where a lack of rain has left four-legged livestock bereft of fresh grasses. Farmers report a more mixed impact on their row crops, with the future of local fruits and vegetables difficult to ascertain until the end of the typical rainy season. 

A mere 10.68 inches of rain was measured at Lake Lagunitas in 2013, the lowest number ever recorded, according to Marin Municipal Water District, which has been keeping tabs since 1879. A December report from the National Weather Service found that a high-pressure ridge in the Pacific Ocean prevented weather systems from landing in California in December, and resulted in many parts of the Bay Area receiving between 5 and 15 percent of normal rainfall last month. The United States National Drought Monitor’s most recent map of California shows the state mostly covered in severe or extreme drought.

That is bad news for West Marin agriculture, and for beef ranches in particular, said Sam Dolcini, the president of the Marin County Farm Bureau. Because the margins for beef ranching are much thinner than they are for dairies, the former suffer more when forage is scarce. “Every rancher I know has bought more hay,” Mr. Dolcini said. And during the winter, feed also costs more. 

December 2012 brought needed rains, but the dry spring and dry fall of 2013 has left fields parched. “It’s the worst of both worlds,” said rancher Bill Barboni II, of Hicks Valley. “It’s a double whammy.”

The fourth-generation rancher said he is using 50 percent more hay than usual at this time of year to compensate for the lack of forage. At a certain point, he said, it is simply more cost effective to sell some cattle earlier than usual. Organic ranchers like him must also abide by United States Department of Agriculture regulations that limit the amount of hay they can feed their herds relative to time spent grazing.  

Mr. Barboni said he has sold about 30 percent of his 800 yearlings earlier than usual. He has not yet sacrificed any of his older herd, though he will if rains do not come soon. Everyone, he said, is in the same boat, meaning less meat produced locally. 

Mr. Dolcini compared conditions to the severe drought that plagued California during 1976 and 1977. “This is as bad, if not worse, than then,” he said.

Marshall rancher Merv McDonald, who has tended beef cattle for 70 years, also plans to sell a portion of his herd. On his land off Marshall-Petaluma Road, he is feeding his animals hay daily—despite the escalating cost. “There is no forage. No one has any grass left,” he said.

If rains do not come, the cattle’s very water supply will also take a hit. Those late 2012 rains filled many of the ponds that local cattle use for water, but ranchers said those ponds are starting to dry up.

While the absence of rain is taking its toll on ranches, the impact on another sector of Marin’s agriculture, row crows, is more complicated. When fall and early winter months are dry, some farmers said they can actually benefit, since it is easier to till the soil to prepare it for planting just before rains arrive in late January, February and what is sometimes referred to as “miracle March.”

Gospel Flat Farm in Bolinas sits on low-lying land—on Pine Gulch Creek and the fringes of Bolinas Lagoon—and there is often a glut of water in the soil. Drier years can increase yields because the ground has a more suitable amount of moisture. 

“In really dry years we can produce more in areas where [normally] fields never dry out, even in the middle of summer,” said Mickey Murch, who farms the land with his family.

Arron Wilder, of Table Top Farm in Point Reyes Station, noted another silver lining. “The lack of rain has helped with weeds,” he said, both because they are more sparse and because it is easier to remove them from dry soil. 

But Dennis Dierks, who runs Paradise Valley Produce in Bolinas, said he would prefer consistent precipitation throughout the season and that rains would help the cover crop he has planted, to bring nutrients back into the land. 

If rains fail to materialize at all this rainy season, farmers agree, they would be in trouble—and locals would find themselves with fewer fruits and vegetables sourced from West Marin.