Weather hazards in cities of East Asia: interacting influences of global warming and urbanization

Abstract

Rapid urbanization and global warming are jointly reshaping weather hazards in East Asia’s megacities and urban agglomerations, which are particularly vulnerable due to high population density, complex urban morphology, and strong regional climate variability. This review synthesizes recent literature on how global warming and urbanization influence weather hazards in East Asian cities and how these hazards translate into broader social and economic risks. Across major urban clusters in East Asia, the literature shows that global warming increases the background probability of extreme events, whereas urbanization primarily modifies their local intensity, spatial distribution, nocturnal persistence and sub-daily timing. Heat hazards are increasingly characterized by persistent nighttime warming and more frequent compound humid-heat events, with their relative prominence varying by regional climate setting. Cities in humid climates exhibit amplified exposure to humid heat due to enhanced moisture availability caused by warming and influences of air–sea interactions, whereas cities in arid climates experience stronger nocturnal heat persistence driven by ventilation constraints, enhanced boundary layer stability, and reduced radiative cooling. Precipitation hazards are increasingly dominated by short localized heavy rainfall influenced by monsoon moisture supply, coastal proximity, topography and urban land-surface effects. At the event scale, urban effects can further intensify compound wind-rain-flood risks during typhoons through interactions between urban surface roughness and storm structure. Beyond physical changes, we summarize impacts of weather hazards on health, labour productivity, infrastructure, and social inequality, highlighting how urban weather hazards evolve into systemic risks. We further identify key knowledge gaps and future directions, emphasizing the need for improved modelling frameworks to address scale mismatches, strengthened urban observational systems to better constrain and validate models, and the development of impact-relevant projections that explicitly account for urban heterogeneity.