December Review

In the next few days I'll have a few posts taking a look back at 2016, but first we're going to do a quick review of December.

High Temperatures

With an average High of -7°C, this December was right in the middle of the pack - a little bit warmer than 2012 and 2013, but quite a bit colder than 2011, 2014 and 2015 which all had average Highs closer to freezing.

Looking at the block of blues, we can see the coldsnap that lasted from the 5th through the 17th.

In terms of the extremes, we had 8 days with Highs below -15°C, which puts us right inline with the colder recent years. We didn't have any Highs below -20°C though, whereas 2008 and 2009 had 5 and 6 of those respectively.

We had 7 days above freezing, which is also a little on the low side. And we didn't have any highs above 5°C, which is a little unusual because 15 of the last 20 Decembers have had at least one day than warm.

I had someone ask what this data would look like in a 3d format, so here we go:

I've played with this type of chart in the past, and I've never really found a version that I'm happy with.

At the most basic level, if you look at the oranges this gives you some sense of how much time we spend above freezing.

Beyond that though, it's very hard to interpret. Even knowing what December 2016's temperatures were like - very cold for the first few weeks, and then warmer towards the end - it's tough to actually see that here.

For a slightly more straightforward look, here is my typical chart of temperature distributions:

This is a nice reminder of the rollercoaster that the last few month have been, with a very cold early-October, a very warm early-November, and a very cold early-December. In the past three months we've swung back and forth between the bottom of the range and the top. In December we didn't break any recent record highs, although we came close a few times.

Low Temperatures

In terms of Low temperatures, December 2016 was again on the cool side of things.

We only had one day below -25°C, but we had ten below -20°C. So this December's deepfreeze was mild compared to years like 2008, 2009 and 2013, but it also wasn't a particularly warm December.

Here is the 3d version of the lows:

And again, I'm not really a fan of this chart. If you look for the dark blues it gives some sense of how infrequently we've seen temperatures below -30°C or -25°C, but that's about it.

Looking at the temperature distribution for the Lows, we again see the recent rollercoaster of a cold October, warm November, and mostly-cold December.

December set two recent record lows, at -27.3°C on the 17th and -24.7°C on Boxing day. Those are just from recent history though, and the all-time historic lows for those days are -42.8°C and -38.3°C respectively (we might set records for high temperature, but it's very unlikely that we'll ever set them for lows).

Update:

Thinking about the 3d charts a little bit more, here's a different version which might be better:

It's the same idea, but this version is rotated so that it's easier to compare the years to one another. Here the cold years (2008 and 2009) show up fairly nicely as valleys, compared to the peaks of the warm years (2002-2006, 2011).

There's still way too much going on, but I think this is better than the earlier version.

Here is the updated chart for the low temperatures: