For temperatures we usually use the Blatchford weather station, which is located near downtown Edmonton - and if you're interested in how temperatures differ between Blatchford and the International Airport, that's covered here.
But when it comes to precipitation, Blatchford is missing a few years of recent data. And so today we'll mostly be focusing on the International Airport, but if Blatchford's numbers are available then they will be included for comparison.
Days with Precipitation
To get things started, this chart shows the number of days each month on which precipitation - either snow or rain - was recorded at the International Airport.
This chart uses a format that we'll be seeing a lot of today, with the recent average as a white line in the middle, and it's surrounded by a band for the 25th-75th percentiles (where things will fall roughly half of the time), and that is surrounded by the recent extremes (highest, second highest, second lowest and lowest since 1995).
The blue line in this chart is the number of days with precipitation for 2017 at the International. April and November were the highest at 16 days, and April's total was higher than any other year since 1995. December was way down at 5 days, although in 1997 December only recorded 3 days.
The green dashed line is the number of days with precipitation at Blatchford, and it was 5 days higher in February, but then 3 days lower in April and October, and 4 days lower November.
Monthly Precipitation
This chart shows the monthly totals for precipitation for the International. Data from Blatchford is included as well, and the International's totals from 2016 are also here for reference.
In 2017 the month that had the most precipitation was July at 90mm, and that's typical. April was well above average (we talked about it here) and was the snowiest and overall soggiest April ever recorded at the International. September was also above average, although nothing record-breaking. In the first chart today we saw that November had 16 days with precipitation, but across those 16 days we only received 20mm of precipitation, and that is right around average.
Blatchford's precipitation is shown as the dashed green line. For the early part of the year it was a close match to the International, but from July onward Blatchford recorded quite a bit less.
Cumulative Precipitation
This chart shows how the precipitation totaled-up throughout the year.
Here we can see the gap that started to open up between the International and Blatchford around May. By the end of the year the International had received 489.6mm versus 376mm at Blatchford, for a difference of 115mm or about 30%.
Yearly Precipitation
This chart shows the history of yearly precipitation totals for the International. Blatchford is missing some of it's historical data, so it isn't included here.
At the International the 489.6mm for 2017 is just a touch below the 496mm it received in 2016. Both of those years were at the high-end of the recent range, although from the 1960s through the 1990s totals in the 500-600mm range weren't uncommon. Precipitation dropped a bit around 2000 though, which we had originally looked at here.
Yearly Snowfall
Switching over to snowfall, this chart shows the snowfall totals for each year back to 1880. It's a combination of data for Blatchford and the International, because Blatchford's data only goes from 1880-2007, while the International's is from 1960-today.
The total snowfall at the International for 2017 was 135.6cm, which is right around the longterm average. Some years are down at 50cm and others are up at 200cm, but the 100-150cm range is very common, and has been since at least 1900.
Monthly Snowfall
I normally like to think about snowfall in terms of winters, rather than calendar years, and so this chart shows the monthly snowfall for the winter of 2016-2017 as the dotted red line, and for the first half of 2017-2018 as the blue.
One of the unusual things about last winter was that most of the snow came in March and April. We just saw that 2017 recorded 135.6cm of snow, but 70cm of that was in March & April, with 43cm in April alone.
As we start the winter of 2017-2018 September and October were both snowier than normal, November was average, and then December was very low. With just 2.8cm of snow, December 2017 was the International's 2nd least-snowy December ever, after 2014 with 2.4cm.
Winter So Far
This chart shows how snowfall totals build-up over the winter (although it's not the same as snowdepth, which we'll look at next).
Our average snowfall total is about 125cm per year, and last winter we were a little bit below average...until the extremely snowy April pushed things over the top. So far this winter we're close to the average, although the mostly snow-less December means we've fallen behind a bit.
Snowdepth So Far
This chart shows the snowdepth at the International and Blatchford. The November-December chinook caused a lot of melting, and Blatchford now sits at 2cm while the International is at 9cm.
Looking at last winter as a comparison, it started off later, but saw significant melting in January, February, and then was snow-free by mid-March, before April threw a bunch of new snow at us.
Precipitation History
Finally we'll end off on this 3d chart of all the precipitation at the International Airport since 1995.
This chart isn't the easiest to read, but I think it does a nice job showing just how dramatic our precipitation is during the May-August monsoon season compared to the rest of the year, and especially compared to the winter months.
If you're interested in comparing 2017 to 2016 last year's write-up can be found here.
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