Zero Snowdepth for 2021

This is a little late, because after a warm start to March things have cooled off a bit, and that threw some uncertainty into the question of whether our snow has officially melted or not.

2020-2021 Snowdepth

In this chart the blue and orange lines are the snowdepth for the winter of 2020-2021 for Blatchford and the International respectively. The light blue stuff in the background shows the average and the range of snowdepths at the International over the past 30 years.

Blatchford's final recorded snowdepth this winter was on March 9th at 3cm, and after that snowdepth has been blank. The International hit 2cm on March 17th, and it hung out there until March 20th. On the 21st it had no meausurement, and since then it has been showing "Trace" amounts of snow on the ground. "Trace" doesn't mean 0cm, but it's close, and eventually it will disappear.

For the winter as a whole both stations jumped to well above average in early-November, and then were mostly flat through mid-February. Things started to drop in the last week of February, and then really fell off a cliff in the first week of March.

2020-2021 Snowdepth - Outlying Areas

For a bit more context, here the snowdepths for Stony Plain and Campsie (about 100km NW of Edmonton) are also shown.

Snowdepth seems to be Environment Canada's least precise measurement, but the Stony Plain and Campsie stations had less snowdepth for most of the winter than the two main Edmonton stations did. Stony Plain's snow disappeared about a week before Blatchford on March 2nd. For Campsie it was March 15th, which was a week after Blatchford and a week before the International.

Recent Winters

This chart has the history of snowdepths and melts for recent winters.

March 21st is pretty early for all of these stations to be snow-free, although 2015 and 2016 were both about a week earlier. But comparied to years like 2020, 2018 and 2013 this winter was about a month ahead.

People always like to joke about "second winter," and just because all of the snow has melted that doesn't mean that we won't get more. In April and May we average another 20cm of new snow, but looking at the snowdepths here that late-spring snow usually doesn't have much of an impact on the ground. 2015 and 2016 both had early melts, which were followed by another week of snow in late-March. And winters like 2017 and 2014 had fairly late melts, and after that the snow showed up again for another week in mid-late April.

Lasting Snow

In this chart each of the narrow blobs shows the length of time for which there was snow on the ground during each winter.

For the winter of 2020-2021 Blatchford had snow on the ground for 122 days in-a-row. That was from and early~ish start on November 8th through to the early finish on March 9th. In recent years 2019-2020 went 141 days and 2017-2018 went 170, while 2014-2015 went 95.

The International had measureable snow on the ground (we ignore the "trace" amounts in the chart) for 133 days, from November 8th through March 20th. 133 days is pretty low for the International: 2016-2017 went 134, 2015-2016 went 121, 2014-2015 went 126. For longer winters recently 2019-2020 was up at 169 days, with 2017-2018 at 172.

2020-2021 Winter In Review: Temperatures

Spring is here, at least according to the calendar. That means that it is time to take a look back at the winter of 2020-2021. However, in Edmonton "winter" definitely does not begin on December 21, and so we will be looking at is the period from November 1st through March 20th. 

Daily High Temperatures

The thin grey line in this chart is the 30-year average High, and November makes a nice start to "winter" because the temperatures in early November mirror late-March. At the start of November our average High is around 4°C, that falls to -8°C by the time winter officially starts in late-December, and then by late-March it's back around 4°C.

For the winter of 2020-2021 then:

• November when from a really warm start, to just below-average for two weeks, to back above average.
• December was well above-average, except for a few cool days from the 11th through 17th.
• January was also well above-average, until temperatures dropped on January 23rd.
• February started below-average, but then dropped into the coldest-in-30-years range from the 6th through 14th. It bounced back up starting on the 19th, though.
• Early March was mostly well above-averarge, with the 10th dipping just below average.

In total we had 88 Highs above-average, including 7 which were the warmest-in-30-years. And that compares to 52 below-average days, including 6 that were the coldest-in-30 years (and were all from February 8-14).

"Warm" Winter Days

From November 1st through March 20th is 140 days, and during that time we had 73 days with Highs which hit 0°C, or 52% of the time. That's above the average of about 64 days, and it is the most since the winter of 2015-2016 which had 81.

Included in that were 40 days which hit 5°C, or 28% of the winter. The average is about 30 days, and this was the most since 2004-2005 which had 42.

This winter did have the distinction of going 29 days in-a-row without a High that hit 0°C, and that was from January 21st through February 18th. The record was 82 days from November 11th 1955 through February 1st 1966, and compared to that our 29 days is not very impressive. But 29 days was the longest since 2011 with 38 days, and it was about a week longer than the typical 21 days that we get each winter.

Daily Low Temperatures

Here are the Low Temperatures for the winter, and they look similar to the Highs with the big coldsnap of late-January through mid-February really standing out, while everything else was quite mild.

We had 85 above-average Lows. That included 7 which were the warmest Lows in 30 years, and March 14th set a record warmest Low at 3.9°C. In comparison there were 55 below-average Lows, including 2 coldest-in-30-years Lows on February 8th at -31.6°C and February 11th at -28.9°C.

Cold Winter Days

Looking at the very coldest days this winter we had 22 Lows hit -20°C, compared to an average of about 25 each winter. The first one was on December 18th, and then the other 21 were all crammed into roughly a month from January 23rd through February 17th.

Included in that were 8 Lows at -25°C, all from February 6th through February 14th. We average about 11 of those each winter. 3 Lows hit -30°C, all in a row on February 7th through 9th. And February 7th was the coldest Low of the year at -33.9°C.

The Horserace

In this chart the red line shows how the temperatures each day compared to the average temperature for the 20th century. When days were above-average days the line goes up, and for below-average days it drops. 

For the start of the winter in November things were fairly flat, but starting in December the lines really started to climb through late-January. The deepfreeze in late-January and February pushed things down for a few weeks, and then they recovered again with the warm March.

As of March 20th this was the 17th warmest November 1st through March 20th, with the Lows as the 16th warmest and the Highs in the 18th spot. During this winter we averaged about 3.2°C warmer than the 20th century average.

If you change the timeframe for this chart to December 1st through March 20th this was the 13th warmest winter, at about 4°C above the 20th century average.

Across Canada

Here we have the relative temperatures for November 1st through March 20th, compared to the 20th century average, for 9 cities across Canada. There are based on the mean daily temperatures (the average of the High and Low), but the High or Low can be selected from the dropdown on the lower left.

As we saw, for Edmonton this was the 17th warmest November 1st through March 20th, and Calgary and Regina were in roughly the same spot. Toronto and Vancouver were both down around #25. For Ottawa and Montréal it was the 10th warmest, for St. John's it was #8, and for Winnipeg it was way up at #7.

Warm and Cold Months

Breaking things down by month the cold February (shown here as the big, blue bubbles) wasn't just in Edmonton, but stretched from Vancouver through Toronto. On the other hand the prairies had a very warm March, while in central Canada it was fairly average.

For November through March for these 9 cities the only below-average months were February for Vancouver through Toronto, and March was just a tiny bit below-average for Ottawa and Montréal. Everything else was in the orange, and generally well above-average.

Warm Winter Days Across Canada

This chart shows the number of "mild" days with Highs of at least 0°C for each Canadian city from November 1st through March 20th. Unsurprisingly Vancouver blows away the competition, with just about every High above freezing. Toronto is next with an average of about 100 days, and Calgary and St. John's are both around 85. Montréal and Ottawa average around 75, with Edmonton at 65. Regina is down at 50, and finally Winnipeg averages 38.

Taking it one step further to 5°C Vancouver is again at the top, with only about a week or two each winter which doesn't hit 5°C. Calgary and Toronto next, both averaging around 50 Highs that hit 5°C from November 1st through March 20th. Edmonton, Ottawa, Montréal and St. John's all average around 30. And then Regina and Winnipeg are around 15.

Cold Winter Days Across Canada

For -20°C Lows each winter Vancouver doesn't even show up, and St. John's hasn't had one since 1994. Toronto might get anywhere from 0-10, for Montréal it is 3-20, and Ottawa it is 5-40. Average are tough though, because each year is all over the place. The prairies are more predictable though, with Calgary averaging around 20, Edmonton around 24, Regina around 40 and Winnipeg around 50. 

For -25°C Lows each winter it is basically just the prairie cities, with Calgary averaging about 8, Edmonton 9, and Regina and Winnipeg at 24. Ottawa also averages around 6, but that bounces from 0-10 each winter.

That brings us to the end of our look back at the temperatures for the "winter" of 2020-2021. Once the snow at the International hits 0cm we will do a recap of this winter's snow.

February 2021 Review

Today we will take a look back at February 2021. It was definitely a cold February, but it wasn't as cold February 2019, and so we will be doing some comparisons between the two.

Let's start with a look back at the winter so far:

Here are the Low temperatures going back to November 2020.

• The middle of November was a little cool, but then things warmed up for a few weeks.
• In mid-December we had one cool week, with December 18th getting all the way down to -20.5°C.
• Then the temperatures jumped back up above average and hung out there for about a month until January 22nd.
• Starting on January 23rd the temperatures dropped below the average, with the Lows hanging out around -20°C until February 5th.
• On February 6th the real deepfreeze kicked in, with the Low hitting -33.9°C on February 7th, and the temperatures staying near the bottom of our 30-year range until things finally warmed up again on February 18th.

So before this coldsnap the winter had been pretty mild, with only a single -20°C Low. But things cooled off in the last week of January, and the deepfreeze really hit in the first week of February. After spending 35 days above-average from December 19th through January 22nd, we then spent 27 days below average from January 23rd through February 18th.

February High Temperatures

Here are the High temperatures for February.

During the coldest part of the deepfreeze we had 6 days with their coldest-in-30-years Highs. Of those February 10th was the coldest, hitting -24.9°C.

February 10th also came closest to breaking an all-time record, but that's partly because February 10th's record -26.1°C from 1922 is actually a little warm. The record coldest-High a week earlier on February 3rd is -36.7°C from 1893.

Once things finally did warm up again we got close to 30-year-warmest Highs on February 20-22, but they were still well below the records which are all above 10°C.

On average in February we get 11 days with Highs of 0°C or warmer, and those show up here as the pick squares. In February 2021 we only had 7 Highs hit 0°C, and that's low. It matches 2018, and it was more than the 3 that we had in 2014, or the 1 warm day in February 2019.

We also had 5 Highs of -20°C or colder. That's a lot, because we average about 1 in February, and most Februarys don't have any. Since 2000 there were 8 in 2019 (again), 3 in 2011, and 1 in 2008 & 2006.

February Low Temperatures

For February 2021's Low temperatures we only had 2 coldest-in-30-years Lows, but we were right near the bottom of our 30-year range from February 6th through 17th.

On-average in February we will have about 6 Lows hit -20°C, including maybe 2 at -25°C. 

In February 2021 we were much colder than average, with 15 Lows at -20°C, including 8 at -25°C and 3 at -30°C. But that was still a long way from February 2019, which had 21 Lows hit -20°C, including 16 at -25C and 3 at -30°C. (...although, 2021's coldsnap did extend back to January, while 2019's was all-February).

One other notable item is that February 22nd's Low was 0.3°C, and since 2000 there have only been 8 other above-freezing Lows in February. February 2017 was the big year with 4 of them.

Cold Days So Far...

At the end of February we have had 22 Lows hit -20°C, which is pretty close to average. That has included 8 Lows -25°C, which is also right on the average. Our 3 Lows at -30°C is a little high, because we average about 1, and many years have none. 

For some trivia, the last 4 winters have all hit -30°C at least 3 times: 3 times in 2017-2018 and 2020-2021 (so far), and 4 times in 2018-2019 and 2019-2020. The last time that we had 4 consecutive winters which hit -30°C 3 times was (wait for it...) in 1972. This is a very specific piece of trivia though, because 2007-2012 had 5 winters which all had at least 2 -30°C Lows. And 1995-1998 had 26 Lows of -30°C crammed into 3 winters.

Unfortunately our deepfreeze-season isn't quite over yet. Between now and the end of the winter we still average around 3 more Lows of -20°C. Those become much less likely after mid-March, although last year on April 2nd 2020 we had our first -20°C in April since the 1980s.    

Days in a Row

The January-February coldsnap felt like it lasted forever, but how did it compare to others?

• We went 29 days without a High hitting 0°C (shown above), and that was the longest since 38 days in 2011.
• We had 11 Highs below -15°C in-a-row, which also happened in 2020 and 2019.
• We had 4 Highs below -20°C in-a-row, while in January 2020 we had 6.

And for the Lows?

• We had 27 Lows in-a-row below -16°C, which was the most since 1982 with 30.
• We had 15 Lows below -20°C, and that's a lot, but is still less than the 18 in 2019.
• We had 6 -25°C Lows, while in 2020 we had 7, and 2019 we had 9.

Warm and Cold Months

On our history of recent months February 2021 shows up as a large, blue bubble. It's not as large as the bubble for the very cold February of 2019, but it is about the same as February 2014.

For January there is a long string of orange bubbles, because our modern Januarys are almost always warmer than the 20th century average for January. But February still flip-flops, including 3 pretty cold Februarys in 2014, 2019 and now 2021.

After a few cold Februarys in the past few years, our average temperatures for February have actually fallen a bit from their peak around 2006. From about 1995-2010 all of our February's were fairly "mild" which is why the average for those years was so high, but after that things started to bounce around. 

For February 2021 the average High of -9.5°C ranked as the 19th coldest since 1881, and the average Low of -18.8°C was the 35th coldest.

February 2021 Across the Canada

So we have seen that February 2021 was cold in Edmonton, but it was also below-average across the West and even to Toronto.

February 2021's large, blue bubbles are still quite a bit smaller than the blue bubbles for February 2019, on the left side of the chart. That was a much colder month on the prairies, and was cold across the entire country. For the prairies February 2021 was around ~5°C below the 20th century average, while February 2019 was ~10°C below.

Snow

On average in February we get 14cm of snow, and 2021 was just below that at 13.3cm. That follows a low January, really low December, and a pretty high November.

For the winter so far we are at 62.8cm, which is below average, and only about halfway to our yearly average of 125cm. In March, April and May we average another 30cm of snow, so we will need to wait to see where things end up.

Looking across the country, Edmonton's snowfall total so far for the winter of 2020-2021 is below all of these other cities, except Vancouver (predictably). St. John's is way up at 220cm, but their average for a whole winter is closer to 350cm.

Snowdepth

Snowdepth is not Environment Canada's most reliable measurement, but at the start of February both of Edmonton's stations jumped up a bit, and then they both dipped back down at the end of the month. At the end of February our average snowdepth is around 22cm, and in 2021 both Blatchford and the International are below that. 

On average our snowdepth really starts dropping around March 10th, so theoretically the start of the big melt might be about a week away.

Looking across the country, after spending most of the winter in the lead Edmonton's snowdepth is now actually below Ottawa, Montreal and St. John's.

March Temperatures

As for March, it averages 20 days with Highs above freezing. That has ranged from 2002 with 8 and 2011 with 11, up to 2010 and 2016 with 29. Last year had 18. 

But March can also have a fair number of cold days. The past 4 Marches have all hit -20°C at least once, and March 2019 had 3 Lows hit -25°C. On average March has about 3 -20°C Lows, but about half of the time there are none.

The average snowfall in March is around 20cm, which is pretty typical for all of our winter months.