For many in Mexico, September 19 has taken on an almost mythical status. Major earthquakes struck on that exact date in 1985, 2017, and 2022, fueling a popular narrative that something sinister links the date itself to seismic activity. The coincidence has become so ingrained in public consciousness that authorities now use the anniversary to run nationwide earthquake drills, and social media lights up every year with warnings and superstitions.
But according to seismologists and historical earthquake data, the numbers tell a different story. When researchers examine the full record of significant earthquakes across Mexico’s history, September 19 does not emerge as the day with the highest concentration of tremors. Other dates throughout the year have registered comparable — or even greater — numbers of notable seismic events, suggesting that the attention on this particular date owes more to memorable, high-profile disasters than to any underlying geological pattern.
Experts note that Mexico sits atop multiple active fault lines and subduction zones, meaning earthquakes can and do strike unpredictably on any day. The repeated coincidence of major quakes on September 19 appears to be exactly that: a coincidence, not evidence of a special seismic calendar.
Curious about the full breakdown of historical earthquake dates in Mexico? Check out the original report for more details.
Source: El 19 de septiembre no es la fecha con más coincidencias de sismos (informador.mx).
Image: martinluff, BY-SA 2.0 (via Openverse).