Alberta's warm weather stretches into October, but how does this fall stack up?
Warmer weather has dominated Alberta’s forecasts since mid-summer
We are officially halfway through fall … no, really.
In Alberta, it may feel more like the early days of September. But here we are, halfway through October, and the forecast is calling for daytime highs in the 20s across much of the province next week.
Seeing the odd day above 20 C in areas like Edmonton and Calgary is not unheard of in October. But the consistency sets this year apart.
Summer-like spikes have been seen before — temperatures set a daily record of 28 C on Oct. 14, 1945 in Calgary and Edmonton.
But in a typical October, Alberta's two largest cities usually see only two or three days with highs in the 20s, and often early in the month.
Edmonton has already had seven days above 20 C this month, and Calgary has had eight.
With more warm days on the way and a pattern that won't let up, will we ever actually see our sweater weather?
How warm has this fall been?
The warmer than normal weather in Alberta this month is not new. The province spent the last half of the summer on a warm note that stretched into the start of the fall.
"We have 13 climate sites here in Alberta," said Kyle Fougere, a meteorologist with Environment and Climate Change Canada.
"Every single site in August was in their top five warmest of all time. And two of them, Edmonton and Grande Prairie, both set records for their warmest August on record."
September saw more of the same with all but one of those sites seeing their top 10 warmest temperatures ever recorded.
Fougere says we have had a repetitive pattern in the atmosphere this season, keeping our temperatures warm.
"We've had this ridge of high pressure that's been over Western Canada basically since the middle of the summer," he says.
Ridges like this one disrupt the jet stream, keeping warmer weather building in Alberta and deflecting storms to the north.
"Alaska, the Yukon, into the Northwest Territories … they're having persistent stormy weather and it's leaving us in this warm sector where we're just having mostly clear skies and above normal temperatures," Fougere says.
The ridge has broken down for a few days at a time — as it did Monday in Alberta, bringing more normal temperatures — but then quickly builds back.
What's in store?
The warm weather stretches on, with forecasts pointing to a run of 20 C temperatures beginning Sunday.
We will see those temperatures dip back closer to normal on Thursday, but overall, warmer weather will likely ride out the fall.
"Through the end of the month and right into the start of November, we're expecting temperatures to generally be above normal," says Fougere.
"There might be the odd system that moves through that will bring us a couple days of cooler weather, but that warm signal is staying in place."
Our "normals" do change, so we won't necessarily see 20 C highs through November.
In mid-October, daily highs should sit around 11 C or 12 C, but by mid-November, normal highs will be closer to 3 C.
"As we get past the autumnal equinox, we start to lose light very quickly," he says. "Because you start losing so much light … the temperatures really start to drop off this time of year."
It's too soon to say how this fall stacks up to previous ones in terms of temperature, according to Fougere.
"It's really hard to make comparisons from what we've seen so far because we know the second half of fall is going to be so much colder than the start of it."
Our planet is changing. So is our journalism. This story is part of a CBC News initiative entitled "Our Changing Planet" to show and explain the effects of climate change. Keep up with the latest news on our Climate and Environment page.
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