A total of 35 recorded tropical cyclones have reached Category 5 strength on the Saffir-Simpson hurricane wind scale in the Atlantic Ocean north of the equator, the Caribbean Sea, and the Gulf of Mexico. Hurricanes of such intensity occur once every three years in this region on average.
Only in six seasons—1932, 1933, 1961, 2005, 2007 and 2017—has more than one Category 5 hurricane formed. Only in 2005 have more than two Category 5 hurricanes formed, and only in 2007 and 2017 did more than one make landfall at Category 5 strength. The years 2016 through 2019 are the longest sequence of consecutive years which all featured at least one Category 5 hurricane each.
Background
A Category 5 Atlantic hurricane is one that is considered by the United States National Hurricane Center (NHC), to have had sustained wind speeds greater than 136 knots (157 mph; 252 km/h; 70 m/s) on the Saffir-Simpson Scale. The NHC considers sustained wind speeds to be those that occur over a one-minute period at 10 metres (32.8 ft) above ground. These wind speeds are estimated by using a blend of data from a variety of sources, which include observations from nearby ships, reconnaissance aircraft, or automatic weather stations and pictures from various satellites.
Officially, from 1924 to 2019, 35 Category 5 hurricanes have been recorded. No Category 5 hurricanes were observed officially before 1924. It can be presumed that earlier storms reached Category 5 strength over open waters, but the strongest winds were not measured. The anemometer, a device used for measuring wind speed, was invented in 1846. However, during major hurricane strikes, the instruments as a whole were often blown away, leaving the hurricane's peak intensity unrecorded. For example, as the Great Beaufort Hurricane of 1879 struck North Carolina, the anemometer cups were blown away when indicating 138 mph (222 km/h).
As of May 2018, a reanalysis of weather data was ongoing by researchers who may upgrade or downgrade other Atlantic hurricanes currently listed at Categories 4 and 5. For example, the 1825 Santa Ana Hurricane is suspected to have reached Category 5 strength. Furthermore, paleotempestological research aims to identify past major hurricanes by comparing sedimentary evidence of recent and past hurricane strikes. For example, a "giant hurricane" significantly more powerful than Hurricane Hattie (Category 5) has been identified in Belizean sediment, having struck the region sometime before 1500.
Officially, the decade with the most Category 5 hurricanes is 2000–2009, with eight Category 5 hurricanes having occurred: Isabel (2003), Ivan (2004), Emily (2005), Katrina (2005), Rita (2005), Wilma (2005), Dean (2007), and Felix (2007). The previous decades with the most Category 5 hurricanes were the 1930s and 1960s, with six occurring between 1930 and 1939 (before naming began).
The most consecutive years to feature at least one Category 5 hurricane each is four, from 2016 to the present year, 2019. Five storms have reached that category in these years – Matthew, Irma, Maria, Michael and Dorian. Of these, Dorian had the highest winds, at 160 kn (185 mph; 295 km/h), while Maria had the lowest central pressure, at 908 mbar (26.81 inHg).
Nine Atlantic hurricanes—Camille, Allen, Andrew, Isabel, Ivan, Dean, Felix, Irma and Maria—reached Category 5 intensity on more than one occasion; that is, by reaching Category 5 intensity, weakening to a Category 4 status or lower, and then becoming a Category 5 hurricane again. Such hurricanes have their dates shown together. Camille, Andrew, Dean, Felix, Irma, and Maria each attained Category 5 status twice during their lifespans. Allen, Isabel, and Ivan reached Category 5 intensity on three separate occasions. However, no Atlantic hurricane has reached Category 5 intensity more than three times during its lifespan. The 1932 Cuba Hurricane holds the record for the most time spent as a Category 5 hurricane (although it took place before satellite or aircraft reconnaissance, so this record may be somewhat suspect). Irma holds the record for the longest continuous span as a Category 5 storm in the satellite era.
Thirty-five Category 5 hurricanes have been recorded in the Atlantic basin since 1851, when records began. Only one Category 5 has been recorded in July, eight in August, twenty in September, six in October, and one in November. There have been no officially recorded June or off-season Category 5 hurricanes.
The July and August Category 5 hurricanes reached their high intensities in both the Gulf of Mexico and Caribbean Sea. These are the areas most favorable for tropical cyclone development in those months.
September sees the most Category 5 hurricanes, with over half of the total. This coincides with the climatological peak of the Atlantic hurricane season, which occurs in early September. September Category 5s reached their strengths in any of the Gulf of Mexico, Caribbean Sea, and open Atlantic. These places are where September tropical cyclones are likely to form. Many of these hurricanes are either Cape Verde-type storms, which develop their strength by having a great deal of open water; or so-called Bahama busters, which intensify over the warm Loop Current in the Gulf of Mexico.
Six of the seven Category 5
hurricanes in October and November (the exception being Michael) reached their
intensities in the western Caribbean, a region that Atlantic hurricanes
strongly gravitate toward late in the season. This is due to the climatology of the area,
which sometimes has a high-altitude anticyclone that promotes rapid
intensification late in the season, as well as warm waters.
Listed by month
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Landfalls
All Atlantic Category 5 hurricanes have made landfall at some location at hurricane strength, and all but two made landfall at some location at major hurricane strength. Most Category 5 hurricanes in the Atlantic make landfall because of their proximity to land in the Caribbean and Gulf of Mexico, where the usual synoptic weather patterns carry them towards land, as opposed to the westward, oceanic mean track of Eastern Pacific hurricanes. Seventeen of the storms made landfall at least once while at Category 5 intensity; 2007 and 2017 are the only years in which two storms made landfall at this intensity.
Many of these systems made landfall shortly after weakening from a Category 5 hurricane. This weakening can be caused by dry air near land, shallower waters due to shelving, interaction with land, replacement of its eyewalls, or cooler waters near shore. In southern Florida, the return period for a Category 5 hurricane is roughly once every 50 years.
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