Lake Champlain Won't Freeze Over This Winter

In a satellite view taken January 31, if you look closely,
almost all of Lake Champlain was ice free.

 After that extreme, but incredibly brief cold snap Friday and Saturday. most of Lake Champlain remains ice free. 

It's been such a warm winter overall that a couple days of frigid weather didn't have much of an effect on ice cover. 

You can see it in the two satellite photos in this post.

The first photo was taken on January 31, before the cold wave hit. You have to look closely, but it looks like the only ice was in the bays and inlets, and in parts of the far northern end of the lake. 

The second photo in the post was taken this morning, February 7, in the morning before clouds rolled in. This of course was after the cold blast, and after a night that brought temperatures down into the single digits above zero around Lake Champlain.

Again, if you look closely, it appearsa large new patch of ice between the southern tip of Grand Isle and Colchester had formed. But there's a ton of open water nearly surrounding that ice. I have a feeling that strong south winds today will break up much of that apparent ice. 

Even if that doesn't happen, there's still large swaths of the lake that are still ice-free.

The lake could still theoretically freeze over this winter, and it would have to be between now and about the second week in March.  After mid-March, it's generally too warm, and the sun angle is too high for ice to form all that much.

In a satellite photo taken this morning, February 7, 
there appears to be more ice than on January 31, but
much of Lake Champlain is still free of ice 

It's highly unlikely the lake will freeze this year. Generally warm weather, with frequent thaws is expected at least into mid-February. 

 You need several weeks of daytimes in the teens and 20s and calm nights with lows in the single numbers above to anything below zero to get the lake to freeze.

Calm nights are key, too. One likely reason more of the lake didn't freeze Friday and Saturday during the subzero cold is because it was awfully windy. The wind stirred up waves, which breaks up ice that's beginning to form, and wells up a bit of comparatively warmer water from below the surface.

Lake Champlain doesn't freeze over as often as it used to, decades ago.  Last year, it came this close to freezing, but there was a tiny hole in the ice way out in the middle that did not disappear in a relatively warm February. 

The last time the lake froze was on March 8, 2019, and then only briefly, for a few days at most. 

Decades ago, before planes regularly flew over the lake, it was probably declared frozen over but there was still small areas of open water that nobody saw. So that's part of the reason why the lake "froze over" so often.

In recent decades, climate change has probably become an increasing influence. In the decade ending in 2020, the lake only froze over completely three times.

For comparison, in the decade ending 1980, it froze seven times.