December 2023 Review

It's time for our look back at the weather in Edmonton for December 2023. 

This will be a little bit shorter than our typical monthly reviews, because the upcoming 2023 Year-in-Review will cover everything else.

It's probably not surprising to hear that December 2023 was warm. But it wasn't just warm, it was one of the warmest. 

The average High of 2.9°C was #1 warmest on record, well ahead of 1999 & 1997. The average Low of -6.7°C was #2, just ahead of 1997 and behind 1959.



High Temperatures

December 1st's High was just below our 30-year average, but after that everything was above-average. We weren't close to any records, except Boxing Day's 9°C missing the 9.8°C record from 1999.

In December we average about 10 Highs above freezing. In 2023 we had 26, including 7 which reached 5°C. 

2023's coldest High was -5.4°C on the 1st, and on average December has 13 Highs below -5°C.

December 2023's 26 above-freezing Highs is the most on record, beating 23 in 1997. (and 2022 had 0!) 

The 7 Highs to reach 5°C is also a lot, but 2020, 2011 & 1997 all had 10.



Low Temperatures

December 2023's Lows were also almost all above average. We didn't have any records though, and most days were a few degrees below the top of our 30-year range.

December 2023's coldest Low was -12.8°C on the 2nd. 

The latest that we had previously gone without hitting -15°C was Christmas Day, in 1954. In December we average 12 Lows of -15°C, and 6 Lows of -20°C, and this year had none.



Cold Days So Far

By the end of December we average around 10 Lows of -20°C. 

So far we have 0, but that also happened in 2019, 2002, 1997, 1987, 1974... 

By the end of December we average around 15 Lows of -15°C. So far we have 0, which had never happened before.



Warm & Cold Months

December is a large orange bubble, with the Highs 8.7°C above the 20th century average, and the Lows 8°C above. 

That follows well below-average Decembers in 2021 & 2022.



Across Canada

December was very warm across the country, and was especially warm on the prairies. Saskatoon's Highs were 10°C warmer than their 20th century average, and all of the prairie cities were at least 7°C warmer.



Snow

In December we average 16cm of snowfall, and the airport actually got some snow this month, unlike in November. 5.2cm is one of the airport's lowest Decembers. 

So far this winter the airport has had a total of 7.9cm, which is its lowest on record. The average would be around 50cm.



Snow Across Canada

For December snow across the country Montréal, Halifax, Ottawa & Calgary all had 10cm+ storms. 

Montréal was on top with 21cm on the 3rd, and a total of 41cm.



Snowdepth

Around town things aren't looking very snowy right now, but the airport and Elk Island were measuring 2~3cm of snowdepth for most of December. 

Technically we had 1cm of snow on Christmas day, but it's still a very low-snow winter so far.



Snowdepth Across Canada

Across the country it's been a low year for snowdepth. 

At the end of the year Edmonton and Winnipeg are the only cities which are still recording any snowdepth, both with 1~3cm.



January

In January on-average we get 12 days with Highs above freezing. But January is also our biggest month for deepfreezes, with an average of 8 Lows of -20°C. January's average snowfall is 22cm.

We'll be back tomorrow with our multi-part 2023 Year-In-Review to take a look at some of the bigger trends for the past year.

2023 is #1 (and what that actually means)

It's getting down to the wire, but on December 27th, 2023 moved past 1981 to become Edmonton's warmest year on record. 

2023's overall average temperature is 3.2°C warmer than the 20th century average.

2023's average High of 11.8°C is 2.7°C warmer than the 20th century average, and #3 warmest on record. The average Low of 1.4°C is 3.5°C warmer, and #1 warmest.

And together they rank as #1. 

That 3.2°C is what gets used to determine the Climatestripes, and it makes 2023 the reddest red so far.

2023 got to #1 with:

• the warmest May on record
• 3rd warmest June & December
• top-10 August & September
• March was the only month colder than the 20th century average

Here each pie slice represents a month, and 2023 has just a single blue piece for March. 

Our other warmest years (1981, 1987, 2016 & 2015) also didn't have many cool months. 

On the other hand, while 2021 had its extreme heatdome summer, it also had a cool February & December.

One thing to note is that our temperature range is much larger during the winter than the summer. And because of that it's much more common to be 10°C above average in January (5°C) than in July (34°C).

So the yearly average is affected more by a warm winter than by a hot summer.

Here's the daily breakdown of how far above/below average 2023 was. 

2023 was warm for most, but even with the record-breaking May and warm summer, 2023 got a lot of its "points" during the warm January, February, November & December.

And our other warmest years also got there thanks to warm months during the winter.

Ranking years based on the daily High & Low temperatures is a pretty broad way to do it. Hourly temperatures would be more precise, but our hourly temperature data only begins in 1953, which would miss 70 years of history. So daily data is the best that we've got.

2023 is #2

When you take all of the daily Highs & Lows for 2023, starting in around late-September the average temperature for 2023 moved into position as Edmonton's 3rd warmest year on record. The Highs rank around 5th warmest, and the Lows are 3rd.

But as of December 14th we have now moved past 2016, and sit as the 2nd warmest year on record. That might be short-lived though, because 1987 also had a very warm December, and it could catch up in the next few days. 

The main dashboard isn't really built for zooming-in, so here are just some images of the horserace:

2016 had been in the #1 spot for a lot of the year, but a cold start to December pushed it down to #3. 1987's really warm September-December pushed it into 2nd. And 1981 was just warm for the whole year. 

In order for 2023 to stay in 2nd spot it will need to be warmer than 1987 was, and this is what the daily Highs looked like for the end of December for those years. 

For the back half of December 1987's average High was -1.5°C (including a record of 8.9°C on Christmas day), and the average Low was -10°C. 

If our temperatures for the rest of the year stay in that range until New Year's, then 2023 will end up right around the #1 & #2 years.

November 2023 Review

How about that November 2023, huh? 

It was pretty mild and dry, but was it unprecedented, or merely precedented? Let's take a look...

It won't surprise anyone to hear that November 2023 was pretty warm. 

The average High of 5.3°C ranked as our 16th warmest overall, and the average Low of -3.7°C was 13th. 

Recently November 2016, 2009 & 2008 were all in the same range.



High Temperatures

November 2023's Highs were above average for almost the whole month, but not by a whole lot. 

The only really exceptionally above average days were the 17th-19th at 14°C, 11.8°C & 10.4°C.

November ends up with 28 Highs above average, and 2 (just barely) below.

November 2023 had 28 Highs above freezing, when the average is around 18. 

November also averages 8 Highs below -5°C, and 2023 had none. 

The warmest High was 14°C on the 17th, and the coldest was -1.5°C on the 30th.

By the end of November on average we have 8 Highs reach -5°C. 

2023 had none, which is unusual, but not all that uncommon. It also happened in 2021, 2015, 2009, 2008, 2004, 2000, 1987, 1981 ...



Low Temperatures

November 2023's Lows were a lot like the Highs: almost all above average, but also not super-hot.

We didn't come close to any records, or to the top of our 30-year range. 

Overall 28 Lows were above average, and 2 were below (just barely).

November averages 3 above-freezing Lows, and in 2023 we didn't actually get any. 

On average it also has 9 Lows reach -10°C, and we had 1.

Last year in 2022 we had 3 -20°C Lows in November.



Warm & Cold Months

November 2023 was pretty warm, and here it's an orange bubble. 

The average High of 5.3°C was 4.8°C above the 20th century average, and average Low of -3.7°C was 4.7°C above. So far for 2023 March is our only below average month.

Across Canada

November 2023 was pretty warm in the west, and average to cool in the east. The Highs ranged from Edmonton & Calgary at 4.8°C warmer than our 20th centruy averages, down to Halifax at at -1.8°C colder than theirs.



The Horserace

With 1 month left in the year, 2023 is still holding onto its spot as Edmonton's 3rd warmest year on record. The Highs are 5th place, and the Lows are 3rd place. Overall the average temperature is about 2.5°C warmer than our 20th century average.

Across the county 2023 is a top-5 warmest year in Edmonton, Calgary & Montréal, and top-10 in Ottawa. For the other cities it's sitting between #16 (Halifax) and #27 (Regina).



Precipitation

In November we average 20.5mm of precipitation. In 2023 we got...basically nothing? 

Blatchford and the airport recorded 0mm, while Stony Plain had 0.7mm. Of a dozen local stations, New Sarepta recorded the most with 0.9mm.

On one hand, it definitely rained downtown on November 19th. But that didn't get recorded anywhere. 

On the other hand, Blatchford also recorded 0mm of precipitation in November in 1885 (which might be accurate) and in 1886 (which is probably an error).

The super-dry November follows an extremely dry October, and a pretty dry September. 

For all 3 months Blatchford's 17.4mm was a bottom-5 year, the airport's 22.9mm was its lowest on record, and Stoney Plain's 36.9mm was bottom-10.

In November we average around 10 days with precipitation. 

In 2023 Blatchford & the airport recorded nothing (although again, the 19th definitely had rain, and there were some flakes of snow), and Stony Plain had 3 days.

This shows the precipitation events that we normally get in September-November, compared to just how quiet 2023's fall has been.

By the end of November we average 423mm of precipitation for the year. 

The dry fall follows a fairly wet summer, so right now the airport is still right on the average with 427mm. Stony Plain is still a little high with 455mm, and Blatchford is a little low with 403mm.



Precipitation Across Canada

This chart has the precipitation for 2023 for these 11 Canadian cities. Halifax is at the top over 1,400mm, and Saskatoon is at the bottom around 230mm.

All of the big cities are pretty close to average for precipitation this year. 

The most unusual one is Vancouver, which is having a roughly bottom-10 year, with 685mm when their average is closer to 1000mm.

For big November storms: 

• Halifax had 50mm on the 18th, 43.9 on the 27th & 20mm on the 22nd 
• St. John's had 43.6mm on the 28th, 27mm on the 1st & 25mm on the 8th 
• Toronto had 20mm on the 8th 
• Vancouver had 20mm on the 11th

Snow

In November we average 20cm of snow. 

In 2023 the airport recorded 0cm, which had never happened before. 

Other low-snow Novembers at the airport were: 

• 2008 1.4cm 
• 2004 1.6cm 
• 1981 0.6cm 
• 1980 0.9cm

Snowdepth

No snow means no snowdepth. 

In recent years, the latest that we'd gone without "lasting" snow on the ground was November 24th, in 2015.

But if we go a bit further back: 

• 2008 made it to December 4th 
• 2005 didn't have substantial snow until February 
• 2004 made it to December 5th 
• 2002 didn't really start until December 30th

Snow Across Canada

For cities which did get snow this November: 

• St. John's topped the list with 27cm 
• Halifax, Ottawa & Montréal were all around 10cm. 
• Calgary had 2 days for 5cm Toronto got 2cm.

Across the country Regina is the only city showing snowdepth, with 1cm. Calgary & Winnipeg (and Edmonton) all had some around Halloween, but it's gone now.

In December we average about 10 days with Highs above 0°C. 

For the Lows, about half of the time December will hit -25°C, but since 1990 there were 3 Decembers which didn't hit -20°C. 

December averages 16cm of snow.