A new study suggests that the impacts of the 2021 heat dome could have been much worse for British Columbians, despite its widespread devastation, when compared to a previously overlooked heat wave during the Second World War.
While the weather and climate conditions of the deadly 1941 heat wave have previously been documented, little is known about its impact in B.C. and across North America - until now.
By scouring thousands of historic newspaper articles and archives, a Simon Fraser University researcher has uncovered the true extent of the 1941 heat wave and believes it could offer valuable lessons in today's more extreme climate.
"The wildfires of 1941 are the main reason I've now reinterpreted 2021 as being a near miss," says Sam Anderson, post-doctoral research fellow, School of Environmental Science.
"You can imagine a future heat wave that could very plausibly initiate many wildfires around Vancouver, like 1941, and then amplify them with post heat wave fire weather, as in 2021."
The research, which took two years to complete, is published in Communications Earth & Environment.
"The 1941 event is the most direct and maybe the only comparison to the 2021 heat wave, considering its magnitude, extent, location, and timing," says Anderson.
"Both 1941 and 2021 were similarly shocking in their severity. But 1941 had a significantly different impact, notably when it came to wildfires. It essentially left Vancouverites trapped between water to the west, and fires everywhere else."
Wildfires surround Vancouver
On the evening of July 17, 1941, an electric set of thunderstorms ignited hundreds of wildfires that surrounded Vancouver to the north, east, and south.
"Persons who make their homes at the end of Lynn Valley earlier watched the spectacular spread of flames as they raced up the trunks of trees in a small green timber stand and transformed the tops into flaring torchs."
Vancouver Sun, July 18, 1941
"Firefighter crews were busy throughout the British Columbia Lower Mainland and Vancouver Island District tonight battling hundreds of small forest fires started by an electrical storm last night and late yesterday as well as several larger blazes which have been burning for nearly a week."
Nelson Daily News, July 19, 1941
When the 1941 heat wave ended, the weather changed to a cool and wet pattern, suppressing wildfire activity.
In contrast, extreme heat and dry conditions persisted in 2021, resulting in out-of-control wildfires that burned the village of Lytton to the ground.
"Vancouver, unlike Lytton, did not burn to the ground in 1941," says Anderson.
"But 1941 reminds us that lightning is capricious in how and where it ignites wildfires, and from the perspective of a sweltering sky, there is little difference between a place like Vancouver and a place like Lytton."
"Unprecedented Heat Wave Hits Pacific Northwest"
The Nome Nugget, July 18, 1941
"All of East An Inferno"
The Windsor Daily Star, July 28, 1941
Another important distinction between the two heat waves is the geographic impact and how this may have affected the death rate.
The 2021 heat dome led to more than 600 heat-related deaths in B.C. with temperatures peaking at 49.6 C, shattering the previous B.C. record of 44.4 C recorded during the 1941 heat wave.
While the 2021 heat dome was largely located in western North America, the 1941 heat wave shifted east across North America.
Around 350 deaths were attributed at the time to the heat wave, either directly via heat stroke or indirectly, primarily via drowning. Most of the reported deaths occurred in eastern North America.
"The screams of ambulance sirens were heard throughout the afternoon in every section of the city."
Minneapolis Morning Tribune, July 25, 1941
"The reported geographical spread of deaths in 1941 suggests that the increased humidity and population density in the east could have been factors," says Anderson.
"In some ways, the fact that the 2021 heat dome did not persist in the east means we may have avoided an even higher death toll."
The two extreme heat waves provide researchers with an opportunity to understand how the impacts of such events change over time.
"This summer marked the five-year anniversary of the 2021 record-shattering heat wave," says Anderson.
"The forgotten 1941 heat wave recontextualizes the 2021 event and together they offer lessons as to how we move forward into a hotter future.
"I think that the optimistic perspective here is that heat waves are climate events, as well as social and cultural events, meaning that their impacts are in part determined by the world that we choose to build."
Anderson says it was notable that newspaper headlines were dominated by the heat wave, even during the middle of the Second World War.
"I was really surprised to see how coverage of the heat wave was not only widespread, but it was front page news, it overtook the war as being the topic of conversation," says Anderson.
"The coverage really paints this picture of an event that was really recognized as being meaningful at the time that it happened."
