Which is the earliest officially recorded Category 5 hurricane in the Atlantic basin?

The 1924 Cuba hurricane is the earliest officially recorded Category 5 hurricane in the Atlantic basin. Reanalysis found that it reached estimated maximum sustained winds of 165 mph on October 19, 1924.

The storm formed in the western Caribbean on October 14 and intensified rapidly after reaching the waters near the Yucatán Peninsula. It struck western Cuba at peak strength, making it one of only two officially documented Category 5 hurricanes to make landfall on the island; the other is Hurricane Irma in 2017.

The word “officially” matters. The 1846 Havana hurricane is widely considered to have reached Category 5 strength, but it occurred before the modern Atlantic hurricane database and lacked reliable wind measurements. That makes the 1924 storm the earliest storm formally classified at the top of the Saffir–Simpson scale.

After crossing Cuba, the hurricane weakened before making landfall in southwestern Florida as a Category 1 storm. It caused around 90 deaths in Cuba, while Florida experienced flooding, crop damage, and heavy rainfall but no reported fatalities.