Frigid temperatures have caused Lake Champlain to fully freeze for the first time since March 2019. Last Friday the National Weather Service declared the lake officially iced over and closed.

Aerial photography and high-resolution satellite imagery were used to determine full ice coverage for the first time in seven years, with the exception of very small gaps, according to Seth Kutikoff, a meteorologist with the National Weather Service in Burlington.

The data comes from polar orbiting satellites passing in a north to south swath and recording images on clear days to show approximate ice coverage on the lake, he said.

Despite the freeze, the NWS cautions people against walking on the frozen lake.

“Even if it’s ice covered, some of that ice could still be very thin,” Kutikoff said.

The NWS has records of ice-related drownings and accidents on Lake Champlain from prior years.

“That database is a good reminder for folks that no ice is truly safe,” he said, particularly on warmer days in the spring “when it’ll be enticing to go on the lake, especially on some of the deeper broad water.”

In decades past, the lake used to freeze over almost every year, according to NWS data, but the freeze is less frequent partly due to warmer weather and climate change.

In 2019, the lake was closed on March 8. In previous years, the lake froze over on Feb. 16, 2015; Feb. 12, 2014; and March 2, 2007. The earliest recorded date of the lake freezing was Feb. 9, 1816, according to NWS data.

On Sunday afternoon, several people were spotted walking across the snow-covered, frozen lake in downtown Burlington, all the way to the breakwater and the lighthouse. Many of them accessed it from the bike path and from behind the ECHO museum, where the Spirit of Ethan Allen III was surrounded by ice.

Mike Shea, owner of Burlington’s flagship cruise ship, is not particularly worried by the freeze as the business is closed for the season until May 3. He said the vessel can sustain the freeze.

“We have a strong steel hull with a framework. It doesn’t affect us at all,” he said.

He’s seen the lake freeze in the past and expects it will pass quickly.

“The weather is going to warm up, and there’ll be a soft breeze and rain, and, all of a sudden, the ice starts moving out,” he said. “It starts moving rather quickly when it warms up.”