PORTLAND — Producers in the U.S. “Maple Belt” say a mild winter has allowed them to tap trees early, but the harvest could be down from last year due to the early onset of spring warmth.

Some producers in maple-rich states such as Maine and New York tapped trees as early as January, atypical in an industry when March is usually the money month. But they might have done so out of necessity: The arrival of consistently warm weather typically ends the maple season, because budding trees produce sap that makes for much less palatable syrup.

Maine’s maple syrup season got started abnormally early this year, with sap buckets visible on trees around Valentine’s Day in the southern part of the state. But producers promise the state’s official sweetener will still be available when the annual statewide Maine Maple Sunday celebration arrives on Easter Sunday.

“This is one of the earliest years I can remember in all my years of doing this,” said Lyle Merrifield, president of Maine Maple Producers and a 30-year industry veteran. “What we’re looking at right now is a little bit too warm.”

Maine has the third-largest maple syrup industry in the country after Vermont and New York.

New York producers expect a smaller harvest than last year, said Helen Thomas, executive director of the New York State Maple Producers Association.

Thomas said she began tapping her own trees on Jan. 22, two weeks earlier than she ever has. She said New York producers will likely have about 70 percent the amount of maple they had last year. Last year, the problem was that the winter lingered much longer, Thomas said.

“We were out trying to tap in snow up to our armpits,” she said. “No snow on the ground at all this year.”

So far, Vermont’s maple season has been inconsistent. Some producers made syrup in late January, and others made syrup throughout February when warmer days allowed for it, according to Matthew Gordon, executive director of the Vermont Maple Sugar Makers Association.

In Ohio, most maple producers are already winding down for the year because of a stretch of warm days.

Maine Gov. Paul LePage symbolically kicked off the unofficial start of maple syrup season by tapping a tree Tuesday. The Republican governor said maple syrup is an industry the state should seek to grow.

Associated Press writer Lisa Rathke contributed from Montpelier, Vermont.