OTIS, Maine — Since 1947, Edwin “Sonny” Colburn has been keeping track of when the water in Hancock County’s Beech Hill Pond goes to ice, and back again.

Never, he says, has he seen a winter like this.

“There were years when we were driving vehicles on the ice on Thanksgiving, and we were ice skating and ice boating the first part of April,” he said Tuesday. “This year, the lake wasn’t frozen over until the morning of January 21st, and the ice went out the 21st of March, the earliest I’ve ever seen it go.”

Colburn, who will be 80 next week, said strong northerly winds blew the last of the ice out of the pond last week.

“It’s the earliest I’ve seen it go,” he said. “I’ve never seen anything like this before. It used to be that fishing season didn’t start here until May, but you can pretty much fish year-round now.”

Greg Stewart, the data section chief in the U.S. Geological Survey’s Augusta office said Tuesday the ice disappeared “very abruptly” this year in rivers in northern Maine.

“Some sites, especially Down East, were very atypical,” he said. “At this point, in terms of rivers, there’s very little ice anywhere. About the only ice still left is in northern Maine, and it’s going pretty quick.”

Keeping tabs on ice out has been a multigenerational interest for Marion Staples, who has lived most of her 82 years in the Washington County community of Grand Lake Stream at the base of West Grand Lake.

“My grandmother’s family started it, I think, and we have records from my family and my first husband’s family that go back to 1878,” she said Tuesday. “The latest it ever went out was May 17, 1888. The earliest was April 2, 2006. This year, I don’t know. Given the weather today, it feels like we’re making ice. It’s not out yet, but this wind today will take its toll.”

Staples said years ago she crunched the numbers and determined that the average date for ice out on West Grand Lake was April 27.

“That may have changed in recent years,” she said. “I don’t know if this is climate change, or just a cycle. We’ll just have to take what comes.”

U.S. Coast Guard icebreaking missions that found no ice to break and snowmobilers who required rescuing after breaking through too-thin ice have seen the effect of early warm temperatures. So has the Maine Department of Conservation, which has been tracking this year’s “ice out” phenomenon.

The department defines “ice out” as “when you can navigate unimpeded from one end of a water body to the other.”

“There may still be ice in coves and along shoreline in some areas,” the Department says, but it’s ice out “when a person can traverse the entire water body without being stopped by ice flows.”

The department says that, given last week’s record-setting warm temperatures, many lakes and ponds south and east of I-95 and Route 9 were “very close to being out [of ice] or are already.”

Tim Thurston, the Department of Conservation’s navigational aids supervisor, said Tuesday that some ice out records that date back more than 100 years have been broken by this year’s early warming trend.

“This year will beat some of the early ice out dates, but now that the weather has returned to normal, other older records may stand,” he said. “In southern and eastern parts of Maine, age-old records for ice out have already been broken, at least according to records kept by towns and individuals that in some cases are more than 100 years old.”

Thurston said he hasn’t had time to look at historical records to determine which lakes are ice-free on a record-setting basis. The first Maine lakes reported ice-free on March 12 were Megunticook Lake in Camden and Chickawauke Lake in Rockland. Most recently, on March 26, Embden Pond and Hancock Pond in Embden were determined to be iced out.

An entry dated March 19 states that “most of Sebago Lake [in the Sebago-Windham area] did not freeze this winter. The [boat] ramps are clear but reportedly the water level is ‘low.’ Be careful.”

Other lakes of note and their ice-out dates, include Damariscotta, March 21; Graham Lake in Ellsworth, March 21; and Phillips Lake (Lucerne) in Dedham, March 22.

Thurston said that, historically, ice out observations were important both for commerce and transportation.

“Back in the days when there weren’t any roads, traveling over the ice was a major source of transportation,” he said. “When the ice got wishy-washy, people couldn’t get from place to place.”

Does Thurston believe climate change is affecting this year’s early ice out?

“I have no comment on that,” he said. “In 2010 we had a lot of early ice out, and it’s very strange that we have it again two years later. But next year it could be a record late ice out.”

The Department of Conservation has a website dedicated to ice out information: www.maine.gov/doc/parks/programs/boating/ice_out12.html