2019/07/14

Hot & Cold Days - Dashboard

Today we are going to take a look at two more interactive dashboards, and these ones will let you look at Edmonton's history of really warm & really cold days.

We talk about temperatures a lot around here, and these old posts have some detailed discussion on what we will see in the dashboards:


But now let's look at the dashboards:

Warm Days Each Year Dashboard


Cold Days Each Winter Dashboard

Both dashboards work the same way, but the warm days are grouped by Year (Jan-Dec) while the cold days are grouped by Winter (Jul-Jun).

Now we will take a look at some examples of how these can be used:

Warm Highs Each Year

The simplest thing we can do with these dashboards is to see all of the warm days for each year. This example image is for Highs of 25°C, but we can change that to 20°C or 30° or even 0°C.

With all of the history we can see which years had a lot or a few warm days, how things have changed over time, and when throughout the year the warm days occur.


Cold Lows Each Winter

And here's the cold version of the previous example, with the number of -25°C Lows each winter. Last winter 2018-2019 had more than average, but over the last century that average has fallen from close to 40 -25°C Lows each winter down to about 10.


Extremes: 33°C Highs

We can also use these dashboards to look at extreme temperatures. In this example we have all of Edmonton's Highs of 33°C or more, going back to 1880.


Late Frosts

Here we are looking at the history of frosts after May 15. To keep things simple we've limited this to recent years from 1985 onwards.


Slow Summers

The summer of 2019 has gotten off to a slow start, with a cold June & early-July.

Here the dashboard shows the number of 25°C days each year between June 1 & July 12. 2019 had 5 days, which is definitely on the low side of things, and is well below the last 4 years, but it isn't record-breakingly cold.


Early Winters

Here we have all of the -20°C Lows that occur really early in the winter, from mid-October to mid-November. The ridiculously cold Halloween of 1984 shows up with its low of -24°C.


Melty Winter Days

This chart shows how many High above freezing we get each January. This is something we've talked a lot about on this blog in the past, because Edmonton has always has mid-winter melts. But in recent January's we are at the top of the range, and it's less variable with most years being up over 10.


Cold Februarys

And finally, the February of 2019 was really cold - but how cold was it? Here we have the number of -25°C Lows each February. 2019's 16 was well below the records from back in the 1930s, but it was about 10 more than any February since 1979.

That's it for our tour of these two dashboards. They provide lots of interesting ways to slice and dice the data for Edmonton's warmest and coldest days.

2019/07/13

Daily Temperatures & Precipitation - Dashboard

Recently I have built a whole bunch of interactive dashboards to help visualize weather data. In the next few posts we will be taking a closer look at them to see how they can be used.

Today we are going to start with an easy one: Blatchford's High Temperatures, Low Temperatures, and Precipitation going back to 1880.



For these instructions I will be linking to fixed images, but this widget will let you try things out.


Daily Temperatures & Precipitation

If you were curious about Edmonton's history of Christmas you can set the data to December 25, and you will get the daily history going back to 1880:
  • The daily High temperatures for each year, along with the 30-year average, and the record warmest & coldest.
  • The daily Low temperatures, 30-year average, and records.
  • The daily Snow (grey), Rain (blue) or total Precipitation (green).
    For 1880-2007 the Blatchford station measured Rain and Snow separately, but that changed and for recent years only the total Precipitation (Rain & Snow combined) is available.
So that's fun. But you can also use this chart to select multiple days:


Weekly Temperatures & Precipitation
Here we have the same chart, but this time "Choose Day(s)" is set to include December 25-31.

Here we have the average temperatures & total precipitation for the whole week from Christmas to New Year's. This could be done for a week, or a few days, or a few weeks.


Monthly Temperatures & Precipitation
Taking things one step further here we are looking at the entire month of December. You could also select several months, to combine the summer months of June, July & August together.


Recent Years

And finally, if more than a century of data is just too much you can use the "Choose Range of Years" to filter the results down to a more reasonable range.

So that's it. It's pretty simple, but it provides a lot of flexibility to poke around through the data. This is just one of several new dashboards, and some of the others are accessible using the tabs at the top of the widget. In future posts we will spend some time going through all of them.

2019/06/30

June 2019 Review / July 2019 Preview

Today we are taking a look back at Edmonton's weather for June, 2019.

High Temperatures

The first week of June was quite cold, and we set a record for coldest-since-1880 High on June 7th at 8.4°C.

Then things warmed up, and on the 12th and 17th we set two warmest-since-1996 Highs, although they were still well below the historic records.

The final two weeks were a little cool, with temperatures mostly hanging out a few degrees below average.


When we look at the numbers June had 4 Highs which hit 25°C, which is about average. 2018, 2016 & 2015 all had really warm Junes, with more than 10 25°C days, but 3-5 is pretty typical.

We also had 17 days which hit 20°C, which is just a little on the low side. 2015-2018 again all had more than 20 20°C days, which was a lot, but 2019 broke that streak.

June 2019 had 1 High below 10°C, with June 7th only hitting 8.4°C. In the last 20 years only 2013, 2003 & 2000 had Highs below 10°C. 2019 also had 3 Highs below 15°C, and that is on the high side of things. In recent years only 2000 and 2003 had more with 5 and 6 respectively.


Low Temperatures

For the Low temperatures we hit two warmest-since-1880 Lows on June 12th at 15.2°C (which tied the old record), and on June 13th at 15.8°C. And then June 7th & 10th were coldest-since-1996 Lows.

We see the same pattern here that the Highs had, with a cold first week, then a warm week, and then temperatures a bit below average to finish the month.


June 2019 had 4 Lows below 5°C, which is more than average. In the last 20 years only 2009 had more with 5. It also had 2 Lows above 15°C though (the two records), and half of the time June doesn't have any.


Warm & Cold Months

When we add up all of the Highs & Lows June 2019's average temperature was 14.9°C. The 20th century average for June is 14.7°C, so 2019 just snuck in above average as Edmonton's 67th warmest out of 138.

The average High of 20.3°C was actually below average, and was only Edmonton's 88th warmest. And the average Low of 9.8°C was above average and was Edmonton's 38th warmest.

Over the past century the average Highs for June have stayed quite constant at around 21°C, but the average Lows have increased from 7°C to 10°C. We looked at how the various months have changed in The Months through the Years.



Looking back over the last year 12 months December and January were very warm, and September and February were very cold. The rest of the months were fairly close to the 20th century average, and June was the most average of all.


With all of the months for the past 20 years we can see that 2015-2018 had a lot of warm Mays and Junes. 2019 ended that warm streak though, with a very average May and June.

And for something new, here's an interactive version of the bubble chart. The sliders at the bottom let you select the range of years from 1880-2019, and the months with the largest differences:



How Warm is 2019 So Far?

So how warm is 2019?

For a full explanation of this chart it's easiest to refer back to the original discussion of it in How warm is it? Generally though, it tracks how much warmer each day of the year was compared to the 20th century average - warm days get points and cold days lose them. The blue and orange background is the range of all the years going back to 1881, and they are grouped together like that because showing each individual year gets too messy. To keep things simple the last 10 years are shown here as a reference.

When we look at all of the daily temperatures right now 2019 is sitting just above the 20th century average. Compared to recent years it is above where 2009, 2011 & 2014 were at the mid-point of the year, but it is below all of the others.

The red line for 2019 starts out strong with the warm January, but then the very cold February dropped it below the 20th century average. The warmish March pushed things back up again, and since then things have been pretty flat.


Monthly Precipitation

June 2019 felt like the rainiest month ever, which was not exactly true. Edmonton's precipitation always ramps up in June and July, and this June was fairly rainy, but it was not extreme.

The International received 86mm, which is just a bit above the average of 72mm, and a bit above the 76mm from 2018.

Blatchford was quite a bit higher at 117mm, which is above average and above the 75th percentile for June. It was also Blatchford's most rainy month since June 2013, which had 118mm. And it was more rainy than any month at the International going back to 2011, which had 150mm. So Blatchford did get a lot of rain, but the rainiest "recent" Junes were 1998 with 162mm at the International, and 1997 with 136mm.

For both stations June was the first above-average month since February.


In terms of days which record precipitation, the International had 18 and Blatchford had 16. The average for June is 14 days, so this month was a little gloomier than is typical.

Precipitation So Far

June was a little rainier than normal, and March-May were all below average, so overall 2019 is still sitting on the drier side of things.

So far the International has recorded 159.8mm, and Blatchford has a little bit more at 164.1mm. That is below average, and right around the 25th percentile.


Even though June was fairly rainy, the International didn't get any giant storms. Its rainiest day was June 7th, with 14.7mm. Blatchford (which isn't included in this chart) had two big days with 24.6mm on June 19th and 23.1mm on the 20th.


July Temperatures


The past few years had warm Mays and Junes, so summer felt like it started early. But 2019 broke that pattern, and so July is where things to start...and where it will also start to end. Right now it feels like summer has barely even begun, but the unfortunate fact is that mid-late July is when our temperatures start trending downward again.

Canada Day 2019

Here's a quick look at the history of Canada Day weather in Edmonton.

Temperatures

Canada Day for 2013-2017 were all quite warm, with Highs between 25°C and 29°C. Last year 2018 was a little cooler though, with a High of only 19.8°C.

The warmest Canada Day was 1924 with a High of 35.6°C. The coldest High was 1912 at only 11.7°C, and the coldest Low was 1919 at 2.8°C.

Over the last century the average High for July 1st has stayed fairly consistent at around 22°C, but the average Low has increased from 9°C to 12°C.


Precipitation

We get at least some rain on Canada about half of the time.

Recently 2012 was a pretty big year with 14mm at Blatchford and 7mm at the International. And 2015-2018 all had a little rain at both stations, ranging from 0.2mm to 2.2mm.

Blatchford's rainiest Canada Day was 1998 with 30.2mm, and the International's was 1973 with 25.4mm.

We will be back with an update once the 2019 numbers are in the books.


Updated for 2019

And so Canada Day 2019 comes in just a bit cooler than 2018, with a High of only 18.6°C, which makes it Edmonton's 16th coldest Canada Day since 1880.

And that actually overstates things, because the temperatures peaked at around 8AM, and then started stopping:

By 11PM it was down to about 8°C, which did probably make this one of Edmonton's coldest Canada Day fireworks shows.


It was a fairly rainy and gloomy day, and Blatchford and the Airport received 6.4mm and 5.2mm of rain respectively. That's a reasonably amount of rain, but it doesn't compare to some of the giant thunderstorms from previous years.

2019/05/31

May 2019 Review / June 2019 Preview

Today is our look back at the weather for May 2019 in Edmonton.

We won't be talking about smoke today, because I haven't found a source for historic air quality data. But after these past few days it is something that I'm going to research a bit more for the future.

High Temperatures

It was a bumpy May, with temperatures cool in the 1st week, warm in the 2nd week, fairly average in the 3rd & 4th weeks, and then there were a few really hot days near the end (and then the smoke arrived),

May 29th's High of 30.6°C set a warmest-since-1996 record, but was still below the warmest-since-1880 record of 32.2°C from back in 1936.


Digging into the numbers a bit more, May 2019's average High of 17.8°C was right on the average for May. In comparison, May 2018's average High was almost 5°C warmer at 22.3°C, which made last year the warmest May ever recorded in Edmonton.

May 2019 had one day which hit 30°C, with May 29th at 30.6°C. That makes 4 Mays in-a-row with days that hit 30°C, and since 1880 that had not happened before.

We had 2 Highs which hit 25°C which is close to the longterm average. It is well below recent Mays, though: 2018 had 13, 2016 had 7, 2015 had 6 & 2015 had 6. Our 11 Highs of 20°C was also about average, but below the 23 in 2018 and 18 in 2017.

And we didn't have any really cold Highs below 5°C, which happened most recently in 2014 & 2015.

May 2018

Just as a quick comparison, here we have May 2018 which was Edmonton's warmest May. Almost the whole month was well above average and was up near the top of the temperature range.


Low Temperatures

Low temperatures followed the same cold>warm>average>warm pattern, with a coldest-since-1996 Low of -4°C on May 5th, and a warmest-since-1996 Low of 12.4°C on May 12th.


The average Low of 5.4°C was just a touch below the 20-year average of 5.6°C. May 2019 had 5 Lows below freezing, compared to an average of 2.5, but we didn't have any Lows of -5°C.


Last Frost

Our final frost was on May 5th, which is two days earlier than the 30-year average of May 7th. In the past 5 years the final frosts have been May 5th in 2019, April 30th in 2018, April 28th in 2017, May 13th in 2016, and May 17th in 2015.


Warm & Cold Months

When we add up all of the Highs and the Lows the average temperature for May 2019 was 11.6°C, which is a little bit warmer than May's 20th century average of 11.1°C. That ranked 2019 as Edmonton's 58th warmest overall since 1880, and well below #1 2018 and #5 2017.

The average High of 17.8°C was Edmonton's 68th warmest, and the average Low of 5.4°C was the 51st warmest.

Looking at the 10-year average (dotted red lines) we can see that over the past century May's average High has crept up from 10°C to 11°C, while the average Low has increased from about 3°C to 6°C. We looked at this in more detail in The Months through the Years.


Our #58 May follows a #52 April and a #49 March, so the past few months have been quite quiet compared to our #5 coldest February, and #16 warmest January.


And here are all of the months for the past 20 years. March, April & May 2019 were all just a bit above average, so their orange bubbles are pretty small.


Precipitation

In May the International Airport received a total of 19mm of Precipitation (rain + snow), with Blatchford just below that at 17mm.  That's well below the May average of 49mm, and below the 39mm that we got last year in 2018.

In recent years other low Mays at the International were 2015 with 17mm, 2011 with 16mm & 2002 with only 8mm.


So far for 2019 most months have had below average precipitation, and so our cumulative total for the year is pretty low.

The average total precipitation at the end of May (the white line) is 130mm, and so far the International (blue line) has had a bit more than half of that with 74mm, while Blatchford (green line) is at 49.5mm. And at this time last year (red line) we were at 114.6mm. June and July are our most reliably rainy months though, so our monsoon season will hopefully start soon.


Snow!

After the late-May heatwave it feels a little strange to talk about snow, but the month did start with a big snowfall, which carried over from the end of April. It was our 8th 5cm+ snowfall of the winter, and it was relatively late in the year for a big storm.


May 2019 recorded 5cm of snow, which is right on the average. Most months of the winter months were fairly close to the average, but December was about double the average, and September was snowier than anything we'd ever seen.


May's 5.4cm is pretty close to long-term average, but we only get snow in May about half of the time, and so a lot of those years get 0cm while others get 10cm+. The previous three Mays - 2016, 2017 & 2018 - had been snowless at the International, and 2019 broke that streak.


For the winter of 2018-2019 as a whole that brings the total snow to 160.6cm (blue line), compared to only 116.9cm for 2017-2018 (red line).


2018-2019's 160.6cm of snow ranks it as the International's 12th snowiest winter since 1960. But it is still well below some really snowy winters like 2002-2003 with 225cm at the International, or 1906-1907 with 239cm at Blatchford.


Remembering back to last fall, we had a very early first snow on September 12th. Then our first lasting snow arrived on November 1st, which was a little bit early. Then in the spring the snow melted down to 0cm again on March 31st, which was right about average. And finally our early May snowstorm meant that the final snow recordings at the airport were on May 4th. So:
  • First snow to last snow: 235 days (7.8 months) from September 12 to May 4th
  • First lasting snow to first big melt: 151 days (5 months) from November 1st to March 31st.


The winter of 2018-2019's 151 days with snow on the ground is not too unusual. It is about week longer than average, and it ranked as the International's 27th longest stretch.

The 235 days from first snow to final snow was pretty unusual though, ranking 7th longest at the International. Recently 2014-2015 was a week longer, at 241 days, while the long-term average has been closer to 200 days. The International's longest "winter" was 250 days in 1964-1965.  


June Temperatures
 

For June temperatures, it is typical for about half of the month to have Highs above 20°C, with maybe a week's worth of days above 25°C. In recent years 2018, 2016 & 2015 all had warm Junes, with almost 2 weeks of 25°C days. And Blatchford hasn't had a frost in June since 1942.