Yet another mild winter for the record books in the Maritimes

CBC meteorologist Ryan Snoddon says this past season capped off a decade of mainly mild winters across the Maritimes.

Warmer than average winters have become more prevalent across the region over the past decade

Ryan Snoddon · CBC News · Posted: Mar 10, 2021 5:00 AM EST | Last Updated: March 10, 2021

It has been another in a string of mild winters in the Maritimes. (Benoit Tessier/Reuters)

What a winter, or lack thereof, across the Maritimes.

For most of the region, snowfall was lower than average and temperatures were well above average.

In fact, this past winter of December, January and February was one of the warmest on record across the Maritimes and northeastern Canada.

Now you may be thinking that March can be long and chilly and that the spring equinox doesn't arrive until the 20th, and that's true.

Meteorological winter (DJF) 2020-21 was very warm in Eastern Canada, even warmest on record for some locations (highlighted in yellow). Only the NWT and some neighbouring stations ended up below normals this past season. <a href="https://twitter.com/hashtag/climate?src=hash&ref_src=twsrc%5Etfw">#climate</a> <a href="https://twitter.com/hashtag/wxtwitter?src=hash&ref_src=twsrc%5Etfw">#wxtwitter</a> <a href="https://t.co/kqH2K5ti74">pic.twitter.com/kqH2K5ti74</a>
—@Pat_wx

However, for most of the region, the three coldest months are December, January and February — also known as meteorological winter.

And temperatures this winter continued a trend that we've been seeing over the past couple of decades.

A closer look into the past 10 years shows that for much of the region, over 60 per cent of the winter months have been warmer than average.

During the last 30 months of winter, most of Nova Scotia, Saint John, Moncton and Miramichi, as well as Charlottetown all saw 18 to 20 winter months above average.

The past 30 winter months of December, January and February across Nova Scotia. Near average is within 1 C of the 30-year normal. (Ryan Snoddon/CBC)

By comparison, just three to six of those 30 winter months have been colder than average, or 10-20 per cent.

The past 30 winter months of December, January and February across New Brunswick. Near average is within 1 C of the 30-year normal. (Ryan Snoddon/CBC)

The averages in this case are the 1981-2010 climate normals used by Environment Canada for comparing temperatures.

Environment Canada is already in the process of updating these normals to the new 1991-2020 numbers. When they are released later this year, we will no doubt be seeing some updated numbers reflecting our warming climate.

Warmer ocean temperatures

When looking at winters over the past decade, it's pretty clear that our warming ocean temperatures are playing a role.

Locations closer to the coast saw more warmer than normal months than those further inland. Warmer ocean water releases heat throughout the winter months, keeping coastal temperatures more mild.

One striking stat is from the Shearwater station near Halifax where the temperature only dropped below the -10 C mark five times this winter. The 30-year average is 33 times per winter!

Environment Canada's climate change report released in 2019 shows that the waters in the Scotian Shelf and Bay of Fundy have been warming decade over decade.

Ocean temperature time series in the Scotian Shelf and one for the Bay of Fundy collected by DFO monitoring programs. (Environment & Climate Change Canada & DFO monitoring programs)

The Gulf of St. Lawrence has also been warming over the past few decades.

In fact this winter, the Gulf has seen a record low amount of sea ice and also record-high water temperatures below the surface.

Historical total accumulated ice coverage for Atlantic Canada. (Environment Canada - Canadian Ice Service)

While near average and even colder than average winters are still occurring here in the Maritimes, the warmer than average months have certainly become more prevalent over the past decade.

It will be interesting to see how this will reflect our new 1991-2020 climate normals. I'll be sure and update you when these numbers are released later this year.