The unprecedented Pacific Northwest heatwave of 1941: Digitized newspapers to understand far-reaching physical and social impacts

The record-shattering North American Pacific Northwest heatwave of June 2021 had catastrophic physical and social impacts on human mortality and morbidity, agriculture, critical infrastructure, cryospheric and hydrologic systems, and wildfire (White et al., 2023).  As a result, the 2021 heatwave was an unprecedented event of global significance; however, due to its extremity and rarity, it is difficult to contextualize how the serious regional impacts vary as a function of social and climatological state.  In other words, how would the impacts of such an event differed if the same magnitude and location of event were to have occurred in the past or future?

Here, we take advantage of archive newspapers to address this knowledge gap and to provide a detailed account of the pan-societal impacts of an extreme 1941 Pacific Northwest heatwave, which was recently identified as being of comparable relative magnitude to the 2021 event (Malinina and Gillett, 2024).  We use hundreds of articles from 17 North American news publications spanning a three-week period including before, during, and after the heatwave.  We find extraordinarily detailed news coverage of the heatwave, with articles reporting: human mortality and morbidity, including deaths that were directly (e.g. heat stress) and indirectly (e.g. high-risk behaviours to cool down) caused by the heatwave; behavioral responses, including altered intra-city mobility; policy responses, including water restrictions in response to water shortages; impacts on agricultural systems, including a high degree of spatial heterogeneity in changes to both production and trade; and physical impacts, including heatwave-caused storms, wildfires, and flooding.  The news coverage also offers valuable context for the heatwave in terms of regional and global events at the time, and policy responses are directly linked to broader global conflict (e.g. decisions regarding wildfire and lumber operations are linked to Canadian efforts in World War II). 

We demonstrate that archive newspapers can offer a remarkable level of detail in characterizing extreme events in the mid-20^th century, especially those that occurred in periods or places with limited physical data, and we are able to use these historical insights to better understand the broader context and impacts of modern extreme events.

 

References

Malinina, E and Gillett, N. The 2021 heatwave was less rare in Western Canada than previously thought. Weather and Climate Extremes 43, 100642 (2024). https://doi.org/10.1016/j.wace.2024.100642.

White, R.H., Anderson, S., Booth, J.F. et al. The unprecedented Pacific Northwest heatwave of June 2021. Nat Commun 14, 727 (2023). https://doi.org/10.1038/s41467-023-36289-3