Yellowknife records its warmest October in decades

A year ago, people were skating by now. This year, lakes are only just starting to freeze. October in Yellowknife was the warmest in most residents’ lifetimes, delivering an unusually long and mild fall.

Online, residents asked each other when the last “brown Halloween” happened. Though a tiny dusting fell on Sunday morning, October 31 was effectively snow-free, a rare though not unheard-of occurrence.

The mean temperature for the month in Yellowknife was 2.61C, a figure beaten only by 2.8C recorded for October 1943. Though October’s warmth was by no means off the charts, this fall feels all the warmer because the seven previous Octobers were significantly cooler.

Between 2014 and 2020, the mean October temperature in Yellowknife was never above 0C. The swing in mean temperature from October 2020 (which had a mean of -1.69C) led October 2021 to feel more than 4C warmer than the same time last year. Across a whole month, that’s a lot.

In 2020, the city’s mean daily temperature never got above freezing after October 12. This fall, the daily average was coming in above 4C as late as October 25.

The unusually warm weather looks set to continue in the short term. Yellowknife’s forecast for the week ahead calls for highs of 2C to 3C, when normally the city wouldn’t get above -5C.

October’s shoulder-season weather oscillates for all manner of reasons and big swings year to year are common. For example, Yellowknifers suffered a week of -10C and below before Halloween in 2012 but enjoyed temperatures above freezing in 2013.

In many respects, the unusual factor isn’t this year but the streak of cooler Octobers that preceded it. On the other side of the equation, truly cold Octobers – with a mean of -4C or below – haven’t occurred so far this century, when they used to happen once or twice a decade.

October warmth this year is similar, though slightly less pronounced, in other NWT communities.

In Inuvik, October this year had a mean temperature of -3.1C. That’s the warmest since 2013, but 2013’s was significantly warmer at a mean of 0.5C. Inuvik has even had years like 2003 where the town managed to record 20-degree weather on some days.

Hay River (3.2C) and Fort Simpson (1.2C) each had their warmest Octobers since 2013, while Fort Smith’s (3.3C) was its warmest since 2003. In the Sahtu, October temperatures were only a little above average.

Meanwhile, if October felt wet to you in Yellowknife, that may be a function of the warmth. While more than a third of the city’s October days brought rain this year, the amount – 17.4 mm – wasn’t especially large. That’s the fourth-wettest October of the past decade in Yellowknife, where residents suffered more than 40 mm in October 2011.

If warmth isn’t your thing, the long-range forecast might bring you some winter comfort.

The formation of a La Niña weather pattern in the Pacific Ocean is expected to eventually result in at-times brutal cold for parts of Canada in the months ahead.

“Environment Canada is indicating that the warmer temperatures we’re enjoying this fall in large portions of the NWT are going to disappear as we get into late November, December, and January,” NWT wildfire operations manager Richard Olsen told reporters last week.

Olsen said that might result in “below-normal temperatures for portions of the western NWT and probably along the average for central NWT.”