It hasn't been a typical summer in Canada this year.

From the East Coast to the West Coast and in between, odd weather patterns including extreme heat and unseasonable cold have been taking Canadians by surprise. According to a senior Environment Canada climatologist, all those ups and downs can be blamed on the jet stream.

  • Listen to the full interview from CBC's The Homestretch by clicking the audio player below.

"So much has been said about the jet stream this summer, I normally talk about it in the winter time!" said David Phillips in an interview with CBC's The Homestretch on Friday. "It's really been affecting the kind of weather we're seeing this summer ... Typically it looks like a bungee cord, stretching from, in the winter time, sometimes from Vancouver Island to Bonavista, in the summer time it migrates further north, maybe over the northern prairies and generally the flow tends to be from south to west. But this year, it has that kind of pattern over the west and in the far east but in the centre of the continent it's dipping way down — it looks more like the winter pattern."

Phillips says that dip is what's causing warm weather in cities like Calgary — which just experienced the second warmest July in 72 years — while also causing cooler temperatures in central Canada.

He says the change in temperature between the Arctic and the south is not as great as it used to be and that's lessening the gradient of the jet stream, causing it to become more loopy or curvy form.

Summer heat to continue in Calgary

That new form means it takes longer for weather systems to work their way across the country, causing prolonged warm or cool periods in regions like Calgary and parts of Manitoba.

In Calgary, that warm weather is expected to continue through August as the jet stream stays put.

"There'll be still a lot of beer drinking weather there in Alberta for the month of August," Phillips said. 

As well, Phillips says the changing weather patterns — including the potential for El Nino to form — could bring good news for western Canada this coming winter.

"The El Nino is the one that we're most watching now. It's the warm water in the Pacific and it does affect our winters, particularly in Alberta, you'll find in the West Coast you'll have more of a Pacific and less of an Arctic flow and so the feeling is that this winter coming up will be, you know, a little less severe than it was last winter — more open and soft."