This week we set a new all-time High on September 11th at 29°C. Last week we set another one on September 7th at 32.2°C, and earlier this year we broke other records on May 5th at 28.9°C, and on February 15th at a scorching (for February) 16.4°C. Four all-time records in one year might sound like a lot, but in 2016 there were 7, and in 2015 there were 5.
One caveat today is that Edmonton has had 3 different weather stations since 1880, and the data varies a bit between them. We looked at the stations here, and saw that the current station often measures temperatures about 0.5°C colder than the previous station did. Normally that's not a big deal, but when we're talking about breaking records even 0.1°C can make all the difference.
So the thing to keep in mind today is that this is more for the sake of trivia than for any great insight. There is a lot of chance involved in breaking a record, because it's often just a matter of being at the right place at the right time.
High Temperature Records Broken Each Year
This chart shows each day of the year along the bottom, and along the side is the year when a new High temperature record is set. When an old record is broken it fades into the background as a grey dot.
Environment Canada's temperature records start in 1880, and during the first few years basically every day was a new record. By the time we reached 1900 things had settled down to about 20 records per year, and from the 1950s onwards the average has been about 4 per year. As we move further along it theoretically gets harder to set new records, because there's more data to compete with.
Recent (2000-2017) High Temperature Records
Here's a closer look at the records which have been broken since 2000.
In 2000 and 2010 we broke 0 records, while 2002 and 2016 both broke 7. It's pretty typical to break 3 or 4 records per year, and so far in 2017 we've broken 4.
Long-Standing High Temperature Records
The earlier charts showed how often records are broken, but this one shows the records that are still standing, and how long ago they were set.
Edmonton has one unbroken High temperature record which goes all the way back to December 12 1880, with a High of 10.6°C. And of the 366 days of the year, 45 of these records were set prior to 1900. Most decades claim about 25 records, but the 1930s hold 49. The 2010s aren't over yet, but so far we're at 24.
Years with Most High Temperature Records
And finally, here are the the years which hold the most High temperature records.
1889 and 1934 have the most records right now, with 10 each. 1910 has 9, 1981 has 8, and then 1936, 1939, 2002 and 2016 all have 7.
So that covers the warmest-High temperature records. Next we're going to flip things around to look at the coldest-Lows.
Low Temperature Records Broken Each Year
Here we have the history of broken records for coldest Low temperatures. It looks quite a bit different from what we saw for the warmest Highs, because after about 1960 the broken records get pretty sparse.
"Recent" (1960-2017) Low Temperature Records
This chart shows all of the Low temperature records which have been broken since 1960, and there are only 19 of them.
Probably the most notable record here was -36.7°C on December 13, 2009, because on that day the Edmonton International also recorded a temperature of -46°C. And that inspired a number of "coldest place in Canada" headlines, and it continues to inspire a number of "Edmonton's winter is 8 months of solid -75°C!" anecdotes.
Long-Standing Low Temperature Records
If we breakdown our Low temperature records by decade, more than 90% of them were set before 1950, and one quarter of them were set in the 1880s. So far in the 2010s we've only set the one, on April 8 2013 at -14.1°C.
There are two other types of temperature records that we haven't looked at yet: coldest-High and warmest-Low. For the sake of completeness we'll take a quick look at those too.
Coldest High Temperature Records
We just saw that we don't break records for coldest-Low very often anymore, but coldest-Highs are a bit more common.
In the last few years we've set records for coldest-Lows on September 8 2014 at 3.8°C, April 30 2013 at -0.2°C, July 22 2011 at 12.6°C, and May 22 2010 at 6°C. None of those were during the winter though, so they might not seem too extreme.
Probably the most notable recent record was December 13 2009, with a daytime High of -28.3°C. That's the same day that had the record-setting Low of -36.7°C, which we had looked at earlier.
And finally, here is how the records are spread out for our warmest-Lows. Earlier we saw that for the warmest-Highs we break about 3-4 records each year, and for the Lows it's a little bit more frequent sitting in the 4-6 per year range. So far in the 2010s we've set 41 warmest-Lows, compared to 24 warmest-Highs.
The most notable thing about these records is probably the giant gap highlighted below:
For June through October, almost all of the temperature records for warmest-Low were set after 1950. The other records we've looked at today were spread out fairly evenly, going back to the 1880s. But for the warmest-Lows during the summer months there are only about 8 remaining records which were set prior to 1950.
One final piece of trivia is that the current record warmest-Low for July 22 was set in 1880, at 20.6°C. The records in Edmonton started on July 11, 1880, and so that one was set in week #2, and it hasn't been broken since.
That's it for today's look at temperature records. When we break a record it always seems momentous, but it actually usually happens a handful of times each year.
VERY COOL.. INTERESTING READ. GREAT INFORMATION!!!
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