In this study, we examine sequential landfalling tropical cyclones (TCs) along U.S. East and Gulf Coasts. We find that Florida and Louisiana are most prone to sequential landfall risk. The minimal time between sequential landfalling TC has decreased for most regions since 1979, although the trend is not statistically significant given limited data. A climate projection indicates a significant increase in sequential landfalls over the 21st century under the SSP5 8.5 scenario, with the chance of a location experiencing a less-than-10-day break between two TC impacts being doubled for most regions. The increases in sequential landfalls in the historical period and projected future climate are both related to increased landfall frequency, even though the storm season has been slightly expanding and may continue to expand. This study highlights a new type of TC hazard resulting from the temporal compounding of landfalls and urges the improvement of coastal resilience.