Widespread impacts and insights contrasted between extreme North American heatwaves in 1941 and 2021

Widespread impacts and insights contrasted between extreme North American heatwaves in 1941 and 2021 | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Widespread impacts and insights contrasted between extreme North American heatwaves in 1941 and 2021 Sam Anderson, Shawn Chartrand This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8379513/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The 2021 Western North American heatwave was among the most extreme events ever recorded and irreversibly impacted physical and social systems. However, recent work has identified an event of comparable magnitude and geographic extent in 1941. Despite its importance for contextualizing one of the most highly studied 21st century heatwaves, very little is known about the impacts of this “forgotten” heatwave of 1941. Here, we review 357 newspaper issues from 25 North American publications from before, during, and after the 1941 heatwave, and provide a quantitative analysis of climate reanalysis, streamflow, tidal, and crop yield data. We uncover widespread impacts including record-shattering temperature observations, water shortages, crop damages, wildfires, flooding, human mortality and morbidity, as well as adaptation via changes to social customs, behaviours, and mobility. We compare with 2021 and find key differences including the continental-scale heatwave evolution, which propagated to Eastern North America in 1941, but not 2021, and the heatwaves’ relation to co-occurring crises of World War II and the COVID-19 pandemic. The 1941 event provides vital context for future heatwaves that would be missed if 2021 is used as the sole reference for what is possible during extreme heat in Western North America. Earth and environmental sciences/Climate sciences/Climate change/Climate-change impacts Earth and environmental sciences/Environmental social sciences/Climate-change impacts Earth and environmental sciences/Environmental sciences Full Text Additional Declarations There is NO Competing Interest. Supplementary Files supplementaryV3.pdf Supplementary Information Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8379513","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":564770749,"identity":"b4e456d1-256a-40ca-a4a5-d2d747815f9e","order_by":0,"name":"Sam 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However, recent work has identified an event of comparable magnitude and geographic extent in 1941. Despite its importance for contextualizing one of the most highly studied 21st century heatwaves, very little is known about the impacts of this “forgotten” heatwave of 1941. Here, we review 357 newspaper issues from 25 North American publications from before, during, and after the 1941 heatwave, and provide a quantitative analysis of climate reanalysis, streamflow, tidal, and crop yield data. We uncover widespread impacts including record-shattering temperature observations, water shortages, crop damages, wildfires, flooding, human mortality and morbidity, as well as adaptation via changes to social customs, behaviours, and mobility. We compare with 2021 and find key differences including the continental-scale heatwave evolution, which propagated to Eastern North America in 1941, but not 2021, and the heatwaves’ relation to co-occurring crises of World War II and the COVID-19 pandemic. 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