On the cusp of Maine Maple Sunday Weekend, syrup producers are reporting normal or better than normal volumes of tree sap, despite the warm winter weather that could have shortened the season.

“They’re about on par with what they’re normally at,” said Lyle Merrifield, president of the Maine Maple Producers Association, which runs the annual event.

Maine Maple Sunday Weekend kicks off at some sugar shacks Saturday. The event promotes the sale of maple syrup and related products from Maine sugar shacks, often run by small family operations or commercial farms statewide.

Karen Giles, a 4-H professor at the University of Maine Cooperative Extension in Somerset County, said milder weather can promote an early start to the sap season. 

“The sap starts running once the temperatures reach about 40 degrees,” she said.

The phenomenon, Giles said, is not unlike trees budding early during a January thaw. The warmer weather makes the tree’s sap flow, which encourages the buds. 

There were tree tappers, she said, who collected sap much earlier than the customary mid-February start, with some starting in January, “which is ridiculously early.”

“Sap’s flowing pretty good in the southern parts of the state, and in the northern parts it’s just getting going,” he said.

Maine sugar shacks produce more than 575,000 gallons of syrup during a normal season, according to the association. That generates more than $55.6 million and supports more than 833 full-time and part-time jobs.

There are about 230 producers in the association, including Alderwood Farms in Limerick. Co-owner Aaron Carroll said he will be open to the public from 10 a.m. to 4 p.m. on Saturday and Sunday. 

Despite the warmer weather, he didn’t start tapping until late February, but volumes have been good.

“It’s been a pretty good year,” he said. “We’ve made some pretty good syrup.”

Giles Family Farm in Alfred will be open on Sunday for the event, according to co-owner Frank Boucher. He said the farm started tapping the week of Feb. 17, about a week earlier than usual. 

Boucher said he was concerned that milder weather might lead to the farm’s trees budding early, which would reduce the amount of sap they produce.

“We worried that we were going to start early, with no snow on the ground and no frost, that it would be a short season,” he said.

Luckily, he said, the farm’s trees are south-facing, so they received less sun. That meant the trees stayed colder, which helped them produce more sap than he expected, not less.

“Actually, we’re having, could be a record year,” he said.

Merrifield said the only weather issue will be a mild spring storm expected to strike over the weekend, but overall he doesn’t think it will scare visitors away.

“I think we’ll have a pretty good turnout across the state,” he said.