Edmonton's Recent Epic Deepfreezes

February's long coldsnap may be over, but grab your hot chocolate (and/or bailey's) because today we're going to talk about Edmonton's recent history of epic deepfreezes.

If you are reading this from the future, the dashboards in these posts tend to break pretty easily, and may no longer match with the text. An archive of the post with the original images is on bluesky.

Coldest Winter(s)

For some context our coldest winter on record is split between 1886-1887 (#1 coldest Lows, #2 coldest Highs, but it is some missing data), and 1955-1956 (#7 coldest Lows, #1 coldest Highs, no missing data). 

1886-1887 is probably the winner though, with a bunch of record Lows.



Longest Deepfreeze

Our longest deepfreeze was famously January 7th to February 1st, 1969. 

Blatchford had 26 straight days with daytime *Highs* below -21°C, with the coldest reaching -30.6°C. The Lows had 26 days in-a-row below -25°C, and 28 in-a-row below -20°C. The coldest was -39.4°C.

The Great Deepfreeze of '69 is pretty unique for Edmonton (as far as recorded history goes), and also compared to the other prairie cities. We looked at it more here.



A "Typical" Deepfreeze

From 1998-2018 we didn't have a stretch of -20°C Lows that lasted longer than 10 days. Most winters topped-out at around 6 or 7.

But since 2019 we've had several deepfreezes that could qualify as "coldest/longest/deepest/etc in a generation".



February 2025

February 2025 was a bit of a baby deepfreeze. It lasted about 3 weeks, but in the middle it was just kind of cold rather than really cold.

February 2025's claim to fame was 20 Lows below -17°C in-a-row, and 20 Highs below -6 in-a-row. 

Neither of those temperatures are super extreme, but those were still both the longest streaks since 1996.



January 2024

The winter of 2023-2024 was pretty mild from the El Niño...except for two weeks in January (and the start of March).

It was cold from January 9th-20th, but the 5 days from January 11th-15th were stuff that we hadn't seen in decades.

Normally I like to be visual with charts, but so many things happened that it would take forever. So here's a boring list instead: 

• 4 Highs in-a-row of -27°C which is the most since 1969. 
• 6 Highs in-a-row of -20°C which tied 2020. 2021 had 7. 
• 2 Highs of -31°C, which was the most since 1954. 
• 3 Lows in-a-row of -36°C tying 1972. 
• 5 Lows in-a-row of -34°C tying 1969. 
• 11 Lows in-a-row of -20°C (2019 had 18) 
• Stony Plain recorded 3 Lows of -40°C. Prior to that it had only recorded 2 in its entire history, going back to 1966. 

The airport is always ridiculously cold, and even it set records. 

• The airport's two coldest Highs ever recorded were -34.4°C on the 12th and -34.3°C on the 14th. 
• It had 3 Lows of -45°C in-a-row, which it had never done before. 
• Its 5 Lows of -40°C in-a-row tied 1969.

This was a generational deepfreeze.

2022-2023

The winter of 2022-2023's claim to fame was not actually a deepfreeze. 

Instead it was nearly two months - from November 28th to January 18th - without a High above freezing. Typically during the winter we will spend 2 or maybe 3 weeks below 0°C, before we get a break.

2022-2023 spent 52 days below freezing, which is twice what we might typically see. It was so long that it tied 1978 as the 3rd longest ever recorded. 1956 has the record with 83 days.

In the middle of that thawlessness we had a short but very deep deepfreeze, with 3 Lows in-a-row below -33°C, with the coldest down to -34.1°C on January 21st.

At the time, 3 Lows of -33°C in-a-row was the longest since 1989. But then January 2024 beat that with 5 in-a-row.



2021-2022

The big deepfreeze of 2021-2022 was from just before Christmas into January. It got to -35°C, and at the time that was the only one since 2009 (then 2024 had 3 more)

Its claim to fame was 17 Lows in-a-row which reached -22°C, which was the most since 1996. And it had 8 Lows of -28°C in-a-row, which tied with 1970.



February 2021

The winter of 2020-2021 was mostly fairly mild, but things cooled off in late-January, which was followed by a February deepfreeze. The coldest it got was -33.9°C,

2020-2021's claim to fame was 27 Lows in-a-row below -16°C, which was the most since 1982.

It also had 15 Lows below -20°C (2019 had 18), and 6 -25°C Lows (2020 had 7, and 2019 had 9).



January 2020

January 2020 was a short but deep deepfreeze. Lows were below -21°C from the 9th to 19th. The 15th got down to -37.6°C. 

Since 1972 our 3 coldest temperatures were: -37.6°C on Jan 15, 2020; -37.7°C on Jan 14, 2024; and -37.8°C on Jan 19, 1996.

January 2020 had 4 -25°C Highs in-a-row, which was the most since 1980 (January 2024 later tied that). 

And it had 6 -20°C Highs in-a-row, which tied 2004 as the most since 1996 (2021 later beat that with 7, and 2024 tied it with 6)



February 2019

February 2019 kicked off our modern era of really long deepfreezes, with Lows below -20°C from February 1st-18th. But even after that it didn't have a big warmup, and stayed fairly cold until March 10th.

February 2019 had 18 Lows of -20°C in-a-row. We've had a bunch of winters get close to that since then, but at the time that was by far the longest since 1996. 

It also had 9 -25°C Lows in-a-row, which was the most since 1996.



What happened in 1996?

A lot of the recent deepfreezes have been "the worst since 1996". So what's the deal with 1996? It was an extremely cold year in Edmonton, and all across the prairies. On Edmonton's climatestripes, it was the last time that we had a blue year.

1996 gave us a long deepfreeze for the winter of 1995-1996, lasting from mid-January to early February. 

And then a few months later the winter of 1996-1997 was also very cold, although its deepfreezes took a few short breaks.



Are things changing?

The past few winters have thrown a lot of really cold days at us. 

We've had 5 -35°C Lows (2 getting down to -37°C), when from 1998-2018 we only had 3. 

In the 8 winters since 2018 we've had 27 -30°C Lows, while the 18 winters from 1998-2017 only had 26.

For -25°C Lows our average has stayed flat around 11, with a few bigger winters like 2018-2019, 2021-2022, and now 2024-2025.

And -20°C Lows still average around 25, even with those long deepfreezes. 

2013-2014, 2010-2011, and 2008-2009 all had a lot of -20°C Lows. They just weren't all in-a-row like we've seen in the past few years, and took little breaks.


The numbers that we've talked about here "days below -20°/-19°/-18°C/etc" are pretty arbitrary, and they are picked to be notable. February 2025 had "20 Lows in-a-row below -17°C!", but if you shift that to -20°C it was only 6. And playing that game works for all of these deepfreezes, to various degrees.

But it's also true that since 2019 we've seen a concentration of exceptionally long, or exceptionally cold deepfreezes, compared to what we would have seen from roughly 1999 to 2018.