Wintertime associations between spatiotemporally-relative synoptic weather types and lagged cardiovascular mortality across various US climate regions

Previous research has shown that a cold environment can adversely impact human health, especially the cardiovascular system. Despite this link, there has been a relative dearth of research into the relationship between wintertime weather variability and cardiovascular-related mortality. Utilizing a newly developed gridded weather typing classification (GWTC), this research systematically examines this relationship across 19 US cities, spanning several different climate zones. Results indicate that a geographically- and seasonally-relative dry and cool (DC) surface weather type relates to significantly increased wintertime cardiovascular-related mortality at all locations, and is associated with a disproportionate number of spike days in cardiovascular-related deaths in each city. Oppositely, a humid and warm (HW) weather type leads to decreases in mortality. Both of these effects peak at 2-6 days after the occurrence of the weather type – reaching magnitudes of +6.6% (DC) to -5.0% (HW) in terms of anomalous mortality – though significant effects can last upwards of 7 to 10 days in some locations. These results are largely consistent across cities in varying climate regions (including Miami, Los Angeles, San Francisco, and Chicago, among others), indicating the relationship between cardiovascular-related mortality and spatiotemporally-relative conditions is important, possibly due to the acclimatization of a city's population to its own climate.