A winter without -20C?

-20C (or -4F) is what started all of this, because it's an important number.

My dog loves the winter, but she loves it a lot less when the temperature is below -20C.

And as someone who spends a lot of time on a bike, -20C is where I switch from mid-level gear to "how many layers am I wearing?" gear.

So for me, it is the point where things go from being cold, to being very cold. Below that there is still "really cold" -25C, "extremely cold" -30C, and beyond. But -20C is roughly where things stop being fun.

And as we reached the end of January 2016, I realized that I had not had a single commute below -20C. And then the end of February 2016 approached, and still no -20C. Normally I can expect one or two rides below -30C, and at least a few below -25C. But not even one ride at -20C? Is that unprecedented?

This chart needs a bit of explanation. It is meant to approximate the number of trips that someone would make if they walk or cycle to work everyday. When I go to work on winter mornings it is typically very close to the daily low temperature, and heading home will be close to the high. This chart counts each of those trips, based on the daytime high and low.

And because I've been walking or cycling to work for 10 years, this chart is roughly the history of all of my really cold days. It is just approximate though, because in 2015-2016 I am still personally at zero -20C commutes. I must have had those two -20 days off.

In this 10 year window, 2015-2016 is definitely special. But personally I find 2010-2011 to be the most interesting. That was my second winter cycling, and it had a lot of cold days - basically 25% of the rides from November through February were below -20C.

2010-2011 set a mental baseline for me, and every year since then has seemed "mild", and now I know why. Looking at the last decade, it seems that Edmonton has some mild winters like 2015-2016, some rough winters like 2010-2011, and then everything else is just winter. So it turns out that my memory wasn't playing tricks on me, and the last 5 years really have all been easier. But I should also probably reset my expectations of "normal" to a winter that wasn't the coldest one in a decade.

Looking at weekday temperatures is a bit of a deliberate cheat, because strangely we get a lot of cold days on the weekends. The score that I'm really keeping track of is "Zero -20C commutes in 2015-2016!" and so far that's still holding. It's an important distinction, because during the week I have to go to work, but for a really cold weekend I can choose not to take the dog to the park, and to stay off the biketrails.

This next chart is not commute-specific, and it shows the overnight lows for all 7 days of the week.  In it you can see that 2015-2016 has had a few additional -20C days, but it's still not a very large number.

And one final comment about winter commuting in Edmonton: it's definitely not all blizzards and -30C. Even in the cold years, someone who goes outside every weekday from November through February will see a lot of mild days.