Seasonality in Mortality and Health: Environmental and Demographic Perspectives

Seasonality is a well-documented characteristic of many health outcomes, with mortality exhibiting distinct seasonal patterns due to environmental and demographic influences. While temperature is a key driver of these variations, additional factors such as air pollution, infectious disease cycles, and socioeconomic disparities also shape seasonal health risks. This commentary discusses methodological approaches for assessing seasonality, highlighting key metrics for summarizing seasonality such as peak-to-trough ratios and attributable fractions. We further discuss how both environmental and demographic factors interact to drive seasonality in mortality as well as the potential impact of climate change on driving future seasonality patterns. Finally, we extend the discussion beyond mortality to explore seasonal variations in other health outcomes. Understanding seasonality in health through interdisciplinary research between epidemiology and demography is essential for public health preparedness.