Analog European Heat Waves for U.S. Cities to Analyze Impacts on Heat-Related Mortality

Abstract

Europe experienced an unprecedented excessive heat event (EHE) in 2003, raising the question: What if a similar EHE were experienced in U.S. cities? This study used an airmass-based meteorological method to develop analogs to the 2003 European EHE for five U.S. cities: Detroit, New York, Philadelphia, St. Louis, and Washington, D.C.; and calculated the potential excess mortality for these analogs. Analogs capture the 2003 EHE's characteristics by determining daily deviations from long-term averages for meteorological variables in Paris, France, expressed as a multiple of the standard deviation for each variable's long-term average. The 2003 daily multiples of the standard deviation measured in Paris for 12 meteorological variables, and daily maximum and minimum temperatures, were transferred to each U.S. city, and multiplied by the corresponding standard deviation calculated for each variable, to produce analog meteorological variables. With these data, an airmass calendar for each city was developed, and excess mortality was calculated using existing city-specific airmass algorithms. Results show the analog EHEs breaking all-time records for maximum and high minimum temperatures in all five cities. Excess heat-related mortality for the analog summer is 2 to over 7 times the long-term average, with New York showing the greatest increases. In all cities, calculated excess heat-related mortality for the analog summer exceeds the hottest recorded summer in 35 yr. These study results could be valuable for public health planning and a wide range of additional reliability or sensitivity analyses.