Subzero Winter Mornings Diminishing In Vermont

Vermont is experiencing a trend toward fewer subzero nights
during the winter. If this keeps up, Bernie Sanders might
need to give up his famous mittens 

A familiar and unwelcome feeling is coming to us here in Vermont tonight: Subzero cold. If you're crazy enough to like that sort of thing, such frigid days are become less common. 

As WPTZ Chief Meteorologist Tyler Jankowski noted on Twitter recently, the number of yearly subzero mornings has declined markedly in the past several decades. At least around Burlington. 

In the mid 1960s, Burlington would go below zero around 27 times each winter.  By 1980 that number was down to 22 days. It declined further to 17 subzero days around 1990, to twelve such days in 2010 and about eight subzero days now. 

I don't have the data for other areas of Vermont, so I don't know how pronounced the trend is elsewhere in the state.

 I suspect part of Burlington's decline in subzero days has to do with the urban heat island effect. Roads and buildings retain some of a winter day's meager heat, and that could sometimes make the difference between a day that would have been a couple degrees below zero vs. a couple days above.

However, climate change has warmed us up, so the relative lack of subzero days in recent years is almost certainly related to a warming climate. 

That's not to say we'll never again have a winter with tons of subzero days. If you get a persistent weather pattern that brings repeated blasts of Arctic air from Canada, we'll still have a lot of frigid days and nights. 

This winter is off to a so-so start in the zero degree derby.  A warm weather pattern in December prevented any really cold air here in Vermont. The pattern flipped at the start of January.  Burlington has already had two days with temperatures of zero or below.  We should get another two tonight and probably Tuesday night. 

It looks like we might have another one or two subzero nights this coming weekend. And remember, it can get below zero all the way into mid or even late March.