As usual, we will start with...
High Temperatures
Here we have the High temperatures for August 2019. The 30-year average for each day is shown by the grey line, and the orange & blue areas in the background are the range of temperatures over that last 30-years. The outermost orange & blue lines are the records for the warmest & coldest Highs since 1880.
And this August we spent a lot of the month below average, with only a few warm days breaking above the 75th percentile.
The little bar graph at the bottom compares the average High each August, going back to 1880. 2019 was about 1.7°C below the 30-year average, and the coldest since 2010. That ranks 2019 as 109th out of 139. The Highs for the past few Augusts had all been above average, and were 2-3°C warmer than 2019.
Let's take a closer look at the numbers:
This table has a lot of stuff going on, but it shows the daily High temperature for each August going back to 2000. The colour of each cell represents how warm or cold the day was, but in August most days are above 15°C so everything ends up as a big red blur. On the chart if you switch from "Absolute Colours" to "Relative Colours" that makes it easier to spot all of the warm & cold days.
With an average High of 20.7°C, August 2019 was on the cool side of the things, in line with 2010, 2004 & 2000. The recent August with the coldest Highs was 2007, averaging a whole degree cooler than this year at 19.7°C.
This August we had 6 days at or above 25°C, while 2014-2018 all had 10-14. And for days which hit 20°C August 2019 had 17, while the last few years were up around 25 or 27.
August 2019 only had one High below 15°C, with the 30th at 13.7°C. That's fewer than 2018 which had 3 cold Highs, and 15 years ago 2002, 2004 & 2005 all had August Highs below 10°C.
Low Temperatures
Here we have our August Lows, which bounced around the average all month.
Normally I say that the Lows are a bit boring compared to the Highs, but the little bar graph at the bottom of this chart is actually really interesting.
August 2019's Lows were 0.3°C below the 30-year average, and about the same as last year.
What is interesting about the Lows is just how much they have changed over time. From the 1880s-1960s the Lows in August were consistently 2-4°C below the recent average. If you flip back to the chart for the Highs from earlier you'll see that they don't have the same pattern at all, and have mostly just bounced around during the past century.
August 2019's average Low of 10.9°C was (unsurprisingly) on the cool side, but was about the same as 2018, 2009, 2006, 2004, etc. The coldest recent August average Low was 2005 at 9.5°C.
We had 1 Low below 5°C, with the 27th at 4.7°C. Last year had 2 cold Lows, and there have been a few others scattered over the past 20 years.
If you flip this dashboard over to Relative Colours you can really see how things cool off towards the end of August as the colours shift towards blue.
Warm & Cold Months
When we combine the Highs & Lows, overall August 2019 was just a touch colder than the 20th century average for August at 0.2°C below the longterm average.
This dashboard can also be switched to show that the Highs were 1.1°C colder than the 20th century average, while the Lows were 1.3°C warmer (which is how we end up just above average).
Something to note is that we've had 4 months of pretty mediocre Highs, with May-August all below or right around the longterm average. Looking at the past few summers we had a lot of warm months with big, orange bubbles, but not this year. To find another 4-in-a-row cold summer we need to go back to 2010, and then to 2005, 2004 & 2000.
Going back to our first chart from today we can set the range to May-August, and the Highs for 2019 ranked 110th out of 139. But on average that was still a degree warmer than summers like 2010, 2005, 2004, 2000, 1999, 1996...
Hot Days
2019's cool summer resulted in an overall lack of hot days, which we can see in this dashboard.
2019's hot-day-season is nearing its end, and so far from May-August we had 20 days hit 25°C, and only 5 hit 28°C. That's pretty similar to years like 2009-2013, but way down from 2014-2018. The past few summers had all been really warm, with 35-54 25°C days, 9-21 28°C days.
So in general the summer of 2019 was a lot cooler than 2014-2018, but not as unusually cold as we might think.
Precipitation
After above-average rain in June & July things calmed down a bit in August, with the Edmonton International a bit above average at 69.8mm and Blatchford a bit below at 49.9mm.
Even though the amount of rain in August was about average, we were above average for the number of rainy days. The average for August is 12 days, and this year Blatchford had 18 days which recorded precipitation and the International had 20 days.
For the year so far Blatchford's total precipitation is above average, while the International is just below.
September Temperatures
I would prefer to forget that September 2018 ever existed, but here is a reminder of just how abnormally cold it was. The colours here are the "Relative" version to make all of those unrelentingly cold days stand out a bit more. More typically though we will have a week or even two of days around 20°C (although in 2019 nothing would surprise me).
For September Lows (in "Absolute" colours this time) we can see that the frosts in blue are fairly rare, but 2018 again was something that we will hopefully not see repeat this year.
And that brings us to the end of our first dashboard-based month-in-review. Hopefully it worked out, and we will play around with the format a bit in the future.
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