Heat wave across Western Canada forecast to last through midweek

Sweltering temperatures stretching from British Columbia to the Ontario border has prompted hundreds of heat warnings, but it's not as intense at the deadly 2021 heat dome inB.C., says a national warning preparedness meteorologist.

Jennifer Smith with Environment and Climate Change Canada told a news conference Monday that while the "epicentre" of the heat is located in Northern California, it is expected to persist over much of British Columbia and into Alberta and Saskatchewan until about mid-week, after whichit will move eastward.

An unrelated heat wave has meanwhile sent temperatures into the 30s in Atlantic Canada.

The weather office has issued more than 40 heat warnings in B.C., whenmore than 20 daily heat records were broken Sunday across the province.

While Environment Canada says some of the heat warnings are expected to be lifted by Tuesday, particularly along the coastline and on Vancouver Island, other regions can expect the heat to continue longer.

It says temperatures in B.C.'ssouthern Interior are expected to climb into the low 40s this week, before moderating on Thursday.

Ashcroft, B.C., was listed as the hottest place in Canadaat 40.3 C, whileLytton set a new daily maximum of 39.9 C, beating the record set in 1953 of 38.9 C.

"Above normal temperatures developed across southernB.C. over the weekend," Smith said.

"The heat will continue there and expand east, affecting Alberta and southwestern Northwest Territories [Monday], Saskatchewan by Tuesday and spreading into Manitoba by Wednesday."

California heat wave drives into Prairie provinces

She said the heat event will be "significant and impactful" but it does not compare to the 2021 heat dome that surpassed heat warning thresholds by "a significant margin."

"That was truly an anomalous and extreme heat wave," Smith told the conference. "The highest temperatures forecast for this event are expected to be lower for the areas that saw the worst heat in 2021."

But, she noted the 2021 heat dome did not impact Saskatchewan and Manitoba.

"With the current heat event, several daily records may be broken across the region throughout the event, but all-time records should not be threatened."

WATCH | The health impacts of extreme heat:

How extreme heat affects your body

1 year ago

Duration 1:28

CBCs senior health and medical reporter Lauren Pelley ran for 20 minutes in a heat chamber set at 40 C while researchers measured the strain that the heat put on her heart, weight and core and skin temperatures. This is what the results showed.

The alerts in B.C. cover much of the lower third of the province, the northeastern part of B.C., inland sections of the central and north coasts, Whistler, the Sunshine Coast, Metro Vancouver, the Fraser Valley, as well as east and inland Vancouver Island.

Environment Canada says Alberta and Saskatchewanwill experience temperatures of at least 30 C, with some parts of Alberta forecast to reach about 35 C by Wednesday.

"High pressure causes air to sink and dry out, reducing cloud cover and leading to hot temperatures," Smith explained.

She warned the hot and dry conditions heighten wildfire risk, "particularly where there are existing fires or there is a precipitation deficit such as in northeasternB.C., northern Alberta and the Northwest Territories."

In the U.S., an excessive heat warning was in effect Monday for portions of states including California, Nevada, Arizona, Oregon, Washington and Idaho.

A high temperature of 128 F (53.3 C) was recorded Saturday and Sunday at Death Valley National Park in eastern California, where a motorcyclist died Saturday from heat exposure and another was hospitalized, officials said.

Wildfire risk

Armel Castellan, another meteorologist with Environment Canada, saidB.C. is "definitely seeing its warmest temperatures over the next couple of days." He said the weather office is now working with the B.C. Wildfire Service and it will meet with emergency management officials in the province to prepare for the risks.

In some regions, wildfire smoke paired with heat will make health risks worse, forecasters warned. For example, the city of Fort St. John in northeast B.C. recorded air quality measurements of 10+, the worst possible, on Monday afternoon while also expecting temperatures in the mid-30s.

The tiny community of Fort Liard, in the southwestern corner of the Northwest Territories, is forecast to hit 30 C until Wednesday, well above its average high of 23 C.

Because this is the first widespread heat event of the year in Western Canada, Smith said health officials are warning of the risks, saying people may not be acclimatized to the hot weather.

WATCH | How to make cities cooler:

Heat is a lot worse in cities. Here's how to fix them

1 year ago

Duration 4:41

With more extreme heat waves expected in the future, some communities are finding ways to become more heat resistant.

"This warm spell is likely to linger into next week, particularly across southernB.C. and the Prairie provinces, though it's a bit early to offer a high confidence forecast this far into the future," she said.

"But, with many outdoor events ongoing for example, the Calgary Stampede or the Winnipeg Folk Festival it's encouraged to take extra precautions against the heat, drink lots of water, stay in the shade and arrange for regular checkups on family members, neighbours and friends in case they may need help."

Smith noted Ontario is right on "the fringe" of the heat wave.

"That ridge is essentially going to be retreating south as it transitions east," she explained. "I would expect some warmer temperatures to touch on northwestern Ontario before that ridge fully moves south and retreats back into the United States."

Worldwide temperature records

Daytime highs around 30 C are forecast across much of Atlantic Canada, with humidex readings close to 40 in New Brunswick and Nova Scotia.

Meanwhile, the European climate service Copernicus is reporting the global temperature in June hit a record high for the 13th straight month.

The agency said June was also the 12th consecutive month that the world was 1.5 C warmer than the pre-industrial average. Most countries agreed to try to limit global warming to 1.5 C as part of the 2015 Paris climate agreement.

Eastern Canada, which was hit by an intense heat wave in mid-June, is one of the regions where temperatures were most above average.

June was also the 15th month in a row of record-high sea surface temperatures, according to Copernicus.

A strong El Nio weather pattern helped drive the spike in global temperatures over the last year, according to the United Nations weather agency. But the World Meteorological Organization warned last month that the last nine years have been the warmest on record even with the cooling influence of a multi-year La Nia event.

"The end of El Nio does not mean a pause in long-term climate change as our planet will continue to warm due to heat-trapping greenhouse gases," said WMO deputy secretary-general Ko Barrett in a June statement.

Later this week, remnants of Hurricane Beryl, which devastated parts of the Caribbean last week, are forecast to move into Ontario and Quebec, bringing rain and a risk of thunderstorms.