Abstract The U.S. coastlines have experienced rapid increases in occurrences of High Tide Flooding (HTF) during recent decades. While it is generally accepted that relative mean sea level (RMSL) rise is the dominant cause for this, an attribution to individual components is still lacking. Here we use local sea-level budgets to attribute past changes in HTF days to RMSL and its individual contributions. We find that while RMSL rise generally explains >90% of long-term increases in HTF days, their spatial patterns also depend on the flooding threshold location and local water level characteristics. Vertical land motion dominates long-term increases in HTF particularly in the northeast, while sterodynamic sea level (SDSL) is most important elsewhere and on shorter temporal scales. We show that the recent SDSL acceleration in the Gulf of Mexico has led to an increase in HTF of more than 220%, a number that is unpreceded both in time and space.