Halloween 2021

We are going to take a quick look back at the history of weather for Halloween in Edmonton. These charts will be updated for 2021 once the final numbers are in.

Recent Halloween History

For Halloween our average High is 4.8°C, and the average Low is -3.8°C.

The past few years have been fairly average. Recently 2013, 2010 & 2007 all had Highs above 10°C. Since 2000 only 3 Halloweens have had Highs below freezing, with 2012 only reaching -6.6°C, 2006 at -4.5°C, and 2003 at -4.9°C. And for wintery Lows, 2003 dropped to -16.1°C, and 1991's Low was -18.6°C.

Full Halloween History

Looking at Edmonton's full history for October 31st, our coldest Halloween by far was 1984, with a Low of -23.7°C and a High of only -17.7°C. The warmest Halloween was just a few years before that in 1981, with a High of 19.9°C.

In terms of Halloween extremes, since 1880 we've had 9 years with Highs that reached 15°C, and 4 years with Lows that dropped to -15°C.

In terms of precipitation Halloween can get rain, or snow, or a mix of both. The Halloween with the most precipitation was 1959, which recorded 4.3mm of rain and 6.9cm of snow.

Halloween Snowdepth

The little columns at the bottom of this chart show the snowdepth on October 31st for Blatchford and the International, going back to when snowdepth records began in the late 1950s.

And Halloween is usually snowfree, although 1984 and 1991 both had 16cm. There was also a cluster of years in 2001-2004 & 2006 which all had a bit of snow.

Halloween tends to be just a tiny bit early for snow on the ground. But within a week or two there's usually snow at the Airport, and sometimes also at Blatchford.

Halloween 2019

Today we're taking a very quick look back at the history of Halloween weather in Edmonton.

Temperatures & Precipitation

The average High on Halloween is has been 4.6°C, and the average Low -3.5°C.

Halloween 2018 was a little bit warm with a High of 8.3°C, 2016 & 2017 (and 2014) were right around average, and 2015 & 2013 were both a bit warm at around 10.7°C.

The last time that we had a below-freezing High on Halloween was 2012 at -6.6°C, and with a Low of -9.1°C

For precipitation 2017 had 6mm and 2015 had 3mm (and there was a gap in data

Trivia:

• Edmonton's warmest Halloween was 1981, which was way up at 19.9°C
• Edmonton's coldest Halloween was 3 years later in 1984, with a high of -18°C and a low of -24°C. 1984's High temperature of -18°C was lower than the Low temperatures of every other Halloween except for 1991.
• Since 1981 Edmonton hasn't recorded a Halloween above 15°C. But prior to that there had been 9 warm Halloweens.
• Prior to 1984 Edmonton hadn't recorded a Halloween below -15°C. But since then we've had 3 in 1984, 1991 and 2004.
• Edmonton's snowiest Halloween was 1882 with 10.2cm of fresh snow.

Snow on the Ground

In recent years the only Halloween with recorded snow was 2017 with 2cm at the International.

The Halloweens with the most snow on the ground were 1984 with 16cm at the International (Blatchford had 15cm that year), and 1991 with 16cm at Blatchford (and 13cm at the International).

Halloween is just a little bit early for snow on the ground, but if you move the slider in this chart to November 7th or 15th the snow starts to pile up.

Halloween

This is a few days early, but today we're going to look at Halloween weather.

Temperature History

In recent years the average high has been 4°C and the average low is -4°C.

But look at 1984: a high of -18°C and a low of -24°C. Crazy. And that high temperature of -18°C was lower than the low temperatures of every other Halloween, except for 1991.

Another strange thing is that we haven't had a Halloween above 15°C since 1981. From 1897 through 1981 there were 9 of them, but there haven't been any since. And from 1880 to 1983 there wasn't a low below -15°C, but since then we've had three of them.

Lets take a closer look at recent history:

Recent Temperatures

The 1980s were my peak-trick-or-treating years. They all blur together, but I remember a lot of parkas - parkas tucked under costumes, parkas over costumes, and maybe even a balaclava one year?

Looking at the history, I guess it wasn't really that cold, but 1984 really was that cold. If I was ever forced to wear a balaclava it would have been in 1984. It is worth pointing out that it wasn't just Edmonton: Calgary's high and low were -16°C and -26°C. But just a few years earlier in 1981 both cities recorded 20°C on Halloween, which was Edmonton's warmest and Calgary's second warmest.

I'd said that the 30-year average high is 4°C, but that's not a great representation because the temperatures actually bounce around quite a bit. In the last 10 years we've had: 2 Halloweens around -5°C; 3 around 5°C; and 5 around 10°C. 

And the average low is -5°C, but the breakdown for the last 10 years is: 2 below -5°C, 2 at around -5°C, and 6 above (or right at) freezing.

So most of the time Halloween here is fall-like, with the occasional years edging into wintery. And just in the last 10 years we've been more consistently above 5°C (80%) than in the 1980s (70%) or 1990s (40%).

Precipitation History

This chart of precipitation is more complicated than I'd like, because it's showing a combination of data from Blatchford (solid lines) and the International (dashed lines), as well as for rain (blue) or snow (b&w). So that's why there are so many lines.

Halloween doesn't get precipitation very frequently, but when it does it's fairly evenly split between rain and snow.

1882 and 1999 are the big snow years at about 10cm, and then there were a few more in the 6-8cm range. And the last "big" rain years with over 2mm were back in the 1960s. 

Finally, Environment Canada has a measurement they call "Snow-on-Ground":

Snow-On-Ground

I've never used this before, and the data for snow depth is a little spotty, so I'm not quite sure how much faith to put in it. 

This only goes back to 1955, and in those last 60 years it looks like 2000-2006 was the real stand-out for most consistently snowy: 6 of those 7 years had 2cm or more snow on the ground. And I honestly don't recall that at all. But since then none of the years show any snow on the ground.