Estimating excess mortality allows quantification of overall pandemic impact. For recent decades, mortality data are easily accessible for most industrialized countries, but only a few countries have continuous data available for longer periods. Since Spain, Sweden, and Switzerland were militarily neutral and not involved in combat during both world wars, these countries have monthly all-cause mortality statistics available for over 100 years with no interruptions. We show that during the COVID-19 pandemic in 2020, Spain, Sweden and Switzerland recorded the highest aggregated monthly excess mortality (17%, 9% and 14%) since the 1918 influenza pandemic (53%, 33% and 49%), when compared to respective expected values. For Sweden and Switzerland, the highest monthly spikes in 2020 almost reached those of January 1890. These findings emphasize the historical dimensions of the ongoing pandemic and support the notion of a pandemic disaster memory gap.