2022/01/10

The Great Deepfreeze of 2021-2022

Is it finally over? Have we finally reached the end of The Great Deepfreeze of December 2021-January 2022? Let's take a look at just how deep this deepfreeze was:

Comparing deepfreezes is a bit difficult, but the temperatures plunged on December 24th, and stayed cold until January 10th. There was a blip in the middle, with a warmup on the night of January 1st and morning of January 2nd, before temperatures plunged again.

For the Highs temperatures, from December 24th to January 9th there were 9 days with the coldest Highs in 30 years. The average High of -21.3°C was the 4th coldest on record, after 1950 (-22.8°C), 1965 (-23°C) and 1966 (-23.3°C).

For the Low temperatures there were 7 days with the coldest Highs in 30 years. The average Low for December 24th to January 9th of -28.4°C was the 9th coldest on record. 1949-1950 has the record with -30.7°C.

 

Cold Highs In-a-Row
We had 4 Highs of -24°C in-a-row. For recent years that ties 2008 and 2004, and the January 2020 deepfreeze went 5 days. The record of 14 was set in 1936. There was also a separate 3-day run of -24°C Highs at Christmas.

We had 7 Highs of -22°C in-a-row, and another 5 in-a-row two days later. 7 days is the most since 1972 had 9. Recently 2020, 2004, 1998, 1996, 1984 and 1982 went 5 days. The record of 16 is from 1969, 1936 and 1934.

 

Cold Highs Each Winter
By the end of the deepfreeze we had 4 Highs reach -25°C, which ties the winter of 2019-2020. That's the most since 1996-1997 had 7. That included 2 Highs of -27°C, which ties 2019-2020. Recently 2003-2004 had 3.

So far we have had 12 Highs reach -22°C, which is the most since 1996-1997 had 15. No other recent winters have had more than 5 of those. Our 17 Highs of -18°C is also a lot, behind 18 in 2010-2011 and 25 in 1995-1996.

 

Cold Lows In-a-Row
From December 24th through January 10th we had 19 Lows in-a-row reach -17°C. That ties February 2019. A bit further back 1996 had 25, and 1982 had 30. The record of 49 is from 1950.

Over the course of the deepfreeze we had 18 Lows in-a-row reach -18°C. That's 3 more than February 2021's deepfreeze, but 1 shy of February 2019 which had 19. A bit further back 1996 had 23, and 1982 had 29. The record of 46 is from 1950.

We had 17 Lows in-a-row reach of -22°C. That is three more than February 2019, and four more than February 2021. That is the longest since 1996, which had 19. The record of 28 is from 1969 & 1950.

We had 8 Lows in-a-row reach -28°C, and another 4-day streak a few days later. 8 days is the most since 1970 had 8. The record of 18 was set in 1936. Since 1985 the longest that we had gone was 5 days.

And finally, we also had 2 Lows in-a-row reach 30°C. Recently February 2021 went 3 days, and January 2020 went 4 (along with 1997, 1996, 1989 and 1982). The record of 16 is from 1887.

 

Cold Lows Each Winter
So far this winter we have had 4 Lows reach -30°C, which ties 2019-2020 and 2018-2019. We have had 13 Lows reach -28°C, which is the most since 1996-1997 with 16.

For -25°C Lows so far we have had 15, which is above the average of 11. And we have had 23 Lows reach -20°C, which is just below the average for a winter. (...but there's still plenty of winter left)

 

The Deepfreeze Season
Historically our season for -25°C Lows stretched from early-November to late-March. In recent decades that has been mid-November to mid-March. -20°C Lows used to stretch from mid-October to mid-April, but now usually stick to mid-November through late-March.

 

Another Epic Deepfreeze?
Are epic deepfreezes getting tiring? From 1999-2018 the longest streak of -20°C Lows we had was 10, and most years went 6~8. Now for each of the past 4 winters we've hit 11+ days, including 18 in 2019, and 17 this winter. (1995-1997 were super-cold, "volcano" winters)

For comparison, while 10+ Lows of -20°C in-a-row is a lot for Edmonton (at least until the past 4 winters), in Regina and Winnipeg it's pretty typical to have a 10~18 day deepfreeze each winter.

This messy chart is just a way to compare our recent deepfreezes of 2021-2021, February 2021, and February 2019 to the 28-day streak from 1950.

 

Outlying Areas
For surrounding stations like the Airport, Stony Plain, St. Albert and Campsie the Highs ãveraged 0.5~1.5°C colder than Blatchford. The Lows averaged 1~5°C colder, with some days reaching 8~10°C warmer downtown.

While Blatchford had 2 Lows of -30°C in-a-row, Stony Plain had 3, and the Airport and Campsie each had 8 (the longest since 1982 and 1996 respectively). The Airport had 7 Lows of -32°C in-a-row, which is its most since 1969, and Campsie's 8 days was the most since 1954.

 

What about Calgary?
During the deepfreeze Calgary was cold too, but their Highs have averaged 3.8°C warmer than Edmonton, with the Lows 2°C warmer. A bunch of Highs were 7~8°C warmer, but for the Lows there were only a few days with big gaps.

We also took a quick look at Calgary's big deepfreeze on twitter here:




Snowdepth
At the end of the deepfreeze the snowdepth at local stations is 40cm+, while the average for mid-January is about 18cm.

For other recent winters the snowdepth in January 2014 reached 45~50cm, and 2011 was 45~70cm depending on the station.


And that brings us to the end of our review of the latest epic deepfreeze of 2021-2022. If you want to see how we covered some other, recent deepfreezes:

2022/01/03

2021 Year-in-Review Part 4: Snow

And finally we have reached the end of our 2021 Year-in-Review Part 4: Snow! How was the snow in Edmonton and other Canadian cities last year?

 
(the Blatchford weather station near downtown Edmonton no longer records snowfall or snowdepth, so most of the numbers today will be from the International Airport.)

Monthly Snow
Here we have the snow for each month (including during the summer). 2021's only snowier-than-average months were May (9cm) and December (31cm). February and November were close to average, while January, March and April were all well below average.

 

Total Snow
This chart has the cumulative snow for year (it looks a little strange because it includes the summer months). 

The gist is that we average about 120cm of snow each year, and in 2021 we only recorded 90cm. So it was low, but not super-low.

 

Snow Across Canada
For these cities across Canada Edmonton's 90cm was 2nd lowest, after Vancouver with 29cm. Toronto, Calgary and Winnipeg were all just over 100cm. Montréal and Ottawa were around 170cm. St. John's was at the top with almost 300cm.

For comparison, here are the monthly snow totals for Edmonton, Calgary, Montréal and St. John's. 

St. John's and Montréal get more snow than Edmonton and Calgary, but it's mostly all crammed into December-March.

 

Last & First Snowfalls
This is a comparison of the snow seasons, with Edmonton and Calgary starting around October 1st and lasting through May 1st. Montréal and St. John's both start in early November, but Montréal's average final snowfall is mid-April while St. John's is mid-May.

 

The Spring Melt
Edmonton had an early spring melt in 2021, with the snow mostly gone (even at the airport) by mid-March, when the average is closer to mid-April.

This one is a little messy, but it shows the spring 2021 snow depths for other cities, and Montréal, Ottawa and St. John's all hung onto their snow a few weeks longer than Edmonton and Calgary (although Alberta did get some late-spring snow which melted off quickly).

 

Fall Snow
Around Edmonton for fall snow the mid-November storm kicked things off, and then the cold and snowy December pushed all of the stations up to 30cm. The average for the end of December is around 14cm.

A messy chart again, but at the end of the year Edmonton's 30cm of snowdepth (in blue) was way out ahead of the pack. Winnipeg and Calgary were around 13cm, while the rest all below 10cm.

 

Snowdepth During the Year
And this is just an example of the snowdepth during a calendar year, with Edmonton as typically the most consistent from November through March or April.

 

Snowstorms
For big, 10cm+ snowstorms 2021 only recorded 2, and they were both in the fall. On November 15 and 16 the International recorded a total of 12.8cm, and on December 13 and 14 there were 14.6cm.

For really big 20cm+ storms (over 2 days):
  • Winnipeg had a 23cm storm in April
  • Montréal had a 25.2cm storm in January, and 21cm storm in February
  • Ottawa had a 21.4cm storm in January, and 22.8cm in February
  • St. John's had a 25.2cm storm in January, and 21cm in February

And that finally brings us to the end of our long look back at the weather for 2021. As always, all of these charts are interactive dashboards with data for 9 Canadian cities.

2022/01/02

2021 Year-in-Review Part 3: Precipitation

Are you ready for our 2021 Year-in-Review Part 3: Precipitation! We will take a look at Edmonton, and some other cities across Canada.

 
Each year Edmonton averages about 438mm of combined precipitation (rain + snow). 

In 2021 the International recorded 362mm, Stony Plain had 328mm, and Blatchford had 266mm. For Blatchford that is a bottom-5 year, going back to 1880. Although recently both 2020 and 2019 were above-average.

There are quite a few stations around Edmonton, and here we have the totals for all of them. 

The airport's 361mm was an outlier compared to the others. St. Albert had 326mm, and the rest were between 247-292mm. So it was a dry year all around the city.

On a monthly basis May and December were well above average, while March, April, June and July were very low. June and July average 161mm, while in 2021 Blatchford had 45mm and Stony Plain had 47mm.

 

Big Storms
Our peak rain season is mid-May through mid-August, usually with lots of summer storms. But even at the International, which was the station with the most rain, there was very little going on this summer.

For large~ish 10mm storms Blatchford recorded 6, and the International had 8. The average is around 12, and in 2020 there were 16.

For large 20mm storms Blacthord had 3 and the International had 3, compared to an average of about 4. Blatchford's largest storm was 29.7mm on May 18th. That was also the International's, but with 40.8mm.

 

Precipitation Across Canada
For cities across Canada the total precipitation ranged from Edmonton down at 266mm, up to St. John's at 1468mm. Calgary, Regina and Winnipeg were all around 350-375mm. Toronto, Ottawa and Montréal were around 800mm. And Vancouver was up over 1100mm.

The total year precipitation is pretty close to the average for cities like St. John's, Vancouver, Toronto and Regina.

The total year precipitation was below average for Montréal, Ottawa, Calgary, and Winnipeg. (and Edmonton was way below average).

 

Big Storms Across Canada
These festive-looking charts show the biggest storms of the year. Winnipeg recorded the biggest single day, with 65.7mm on August 20th. Regina recorded 54.8mm on June 11th, and Toronto had 56mm on September 22nd.

As usual, St. John's is the winner for most big storms, with 5 40mm+ days. That included 50mm on September 19th. Vancounver had 4 40mm+ days, including 50.9mm on September 17th.

2022/01/01

2021 Year-in-Review Part 2: Temperatures Across Canada

And now, it's our 2021 Year-in-Review Part 2, as we look at temperatures in 9 major cities across Canada.

Now let's take a look across Canada:

High Temperatures
For the High temperatures, 2021 is a top-10 year east of Alberta:
  • Regina #8
  • Winnipeg #2
  • Toronto and Ottawa #5
  • Montréal #3
  • St. John's #7
Vancouver, Edmonton and Calgary all had the summer heatdome, but the average temperature got knocked down by some cold days.

Months with below-average Highs (blue bubbles) were tough to find this year:
  • February was cold for Vancouver through Toronto.
  • May was a little cool for Vancouver through Regina.
  • July was cool for Toronto through St. John's.
  • December was cold in Vancouver, Edmonton and Calgary.

For hot Highs, it was a top-10 year for +30°C days for most of these cities with the exception of Toronto and Ottawa. And that included #1 for Edmonton and Winnipeg, #2 for Calgary and #3 for Vancouver.

 

Low Temperatures
For the Low temperatures 2021 ranged from #2 in Montréal to #26 in Toronto. For Calgary, Montréal, Ottawa and St. John's 2021 had top-10 warmest Lows.

And the months in blue with below-average Lows were:
  • February in Vancouver through Toronto.
  • April in Regina and Winnipeg.
  • May for Ottawa through Regina.
  • July in Ottawa.
  • November in Toronto and Ottawa.
  • December in Vancouver through Regina.

For -20°C Lows Edmonton was a little above the recent average, while the rest of the cities here were a little below.

And for -25°C and -30°C Lows Edmonton and Calgary were both a little above average, while Regina and Winnipeg were pretty typical.

 

Climate Stripes
When we combine the Highs and Lows, the overall mean temperatures for 2021 ranged from #1 warmest in Montréal to 28th warmest in Vancouver. It was top-10 for Edmonton, Calgary, Regina, Winnipeg, Ottawa and St. John's, and #11 for Toronto.

For 2021's climate stripes all of these cities are pink or red, ranging from 0.6°C warmer than the 20th century average, up to 2.3°C warmer for Montréal.

 

Montréal
2021 was Montréal's #1 warmest year overall, with an average temperature 2.3°C above the 20th century average. The only below-average month was July, which was just a little cool. That follows 2020 which was in 6th spot.

For Highs Montréal had 205 above-average days, and 160 below. That included 9 new daily records. For the Lows it had 228 above-average and 137 below, including 8 new records.

And this is how Montréal's path to its #1 warmest year went. The Highs were 3rd warmest and Lows were 2nd warmest, which combined for the warmest overall. , It was a pretty consistent climb for the whole year, but there's a bit of a flat spot visible during the fairly average July. 


 
All Cities Combined
With the data for all 9 cities smooshed together this was the 7th warmest year overall, with Highs as #4 and Lows as #9.


That brings us to the end of Part 2 of our 2021 Year-in-Review. Part 3 will be about Precipitation, and Part 4 will be snow. These charts are only a sampling of what's available, and the dashboards include the full data for all 9 cities.