Exposure to precipitation from tropical cyclones has increased over the continental United States from 1948 to 2019

Extreme precipitation from tropical cyclones can generate large-scale inland flooding and cause substantial damage. Here, we quantify spatiotemporal changes in population risk and exposure to tropical cyclone precipitation in the continental eastern United States over the period 1948–2019 using high-resolution in-situ precipitation observations. We find significant increases in the magnitude and likelihood of these extreme events due to increased rainfall rates and reduced translation speeds of tropical cyclones over land. We then develop a social exposure index to quantify exposure and risk of tropical cyclone precipitation as a function of both physical risk and socio-economic activities. Increased social exposure is primarily due to the increased risk of tropical cyclone precipitation, but there are regional differences. We identify exposure hotspots in the south-eastern United States, where rapid population growth and economic development amplify societal exposure to tropical cyclone hazards. Our multi-scale evaluation framework can help identify locations that should be targeted for mitigation and adaptation activities to increase their climate resilience.