Hurricane Milton Joins Rare List Of Atlantic Basin Category 5 Storms

H​urricane Milton put its name on the rare list of Atlantic Basin Category 5 hurricanes Monday, joining Beryl from earlier this season.

C​ategory 5 hurricanes occupy the most elite status in the Atlantic Basin. One hundred years of history has shown they have preferred locations and times of year, but there are also outliers, especially in recent years.

Milton and Beryl are the latest members: Milton became a Category 5 at 11:55 a.m. EDT Monday, joining Michael from 2018 as only the second Gulf of Mexico hurricane to hit this intensity in October since satellite detection of storms began in 1966, according to Dr. Phil Klotzbach, a tropical scientist at Colorado State University.

Earlier this season, Beryl became the record-earliest Category 5 in any Atlantic hurricane season on the evening of July 1, 2024. Beryl leapfrogged 2005's Hurricane Emily - the previous earliest Cat. 5 - by a whopping 15 days. That was just one of the many early-season records Beryl shattered.

Category 5 is the highest rating a hurricane can reach: Maximum sustained winds of 157 mph or higher on the Saffir-Simpson Hurricane Wind Scale ​are required for a hurricane to reach this intensity. If you're more familiar with the EF scale for tornadoes, that's equivalent to estimated winds in an EF3 tornado or stronger.

Prior to Milton and Beryl, there had only been 40 such Cat 5 hurricanes in the Atlantic Basin since 1924, according to NOAA's historical database.

It's even rarer to have two Category 5 storms in a season: Just five other Atlantic Basin seasons have produced two or more Category 5 hurricanes since 1950, Klotzbach said in a post on X.

T​he most recent year was 2019 when Dorian and Lorenzo hit that strength. 2005 had the most with four, including Emily, Katrina, Rita and Wilma.

T​here have been 10 Category 5 Atlantic hurricanes since 2016: Besides Beryl and Milton, this most recent spate of Category 5 Atlantic hurricanes also includes Lee in 2023, Ian in 2022, Dorian and Lorenzo in 2019, Michael in 2018, Maria and Irma in 2017 and Matthew in 2016.

That four-year streak from 2016 though 2019 with at least one Category 5 hurricane was the longest on record.

There have been long "droughts" as well: P​rior to 2016's Matthew, the Atlantic went eight consecutive hurricane seasons without a Category 5. There was another eight-year stretch between hurricanes Allen and Gilbert, from 1980 to 1988.

They are most common in the peak of hurricane season: September is when Category 5 hurricanes have occurred most often, by far. But they have also happened at least a half dozen times each in August and October.

This encompasses the most active period of hurricane season. That's because all of the favorable conditions and ingredients for development are most likely to overlap over a large area of the Atlantic Basin.

H​ere's where in the Atlantic they have most commonly formed: The map below shows, in red segments, the locations where hurricanes have reached Category 5 intensity, including Hurricane Beryl early this season.

O​ther than the oddity that was 2019's Hurricane Lorenzo in the far eastern Atlantic, you'll notice almost all of them happen in the same general area, from the southwest Atlantic Ocean north of the Lesser Antilles into the Caribbean Sea and Gulf of Mexico.

T​hese areas are so conducive to strengthening because they have a supply of deep, warm ocean water, lack hostile shearing winds in the heart of hurricane season and feature a parade of disturbances known as tropical waves, which act as seeds for development. The supply of deep, warm ocean water that serves as fuel for hurricanes is highest in the Atlantic Basin in these areas, particularly the Caribbean Sea.

H​urricanes don't hold onto Category 5 intensity for long: On average, a hurricane maintains Category 5 status for just under 24 hours.

T​hat's because intense hurricanes typically undergo one or more eyewall replacement cycles. During one of these, the hurricane's intense ring of thunderstorms around its eye is surrounded by a new outer ring.

W​hen that happens, the hurricane's wind intensity drops temporarily as the former eyewall is choked off. It usually intensifies again when the new outer eyewall is pulled inward, leading to a larger hurricane.

Several Category 5 hurricanes reached that intensity multiple times during their lifetime.

H​urricanes Allen (1980), Isabel (2003) and Ivan (2004) each soared to Category 5 intensity three separate times in their journeys.

T​he November 1932 Cuba hurricane (78 hours) and Hurricane Irma in 2007 (77 hours) spent the longest combined time at Category 5 strength, according to NOAA's database.

Only four hurricanes on record have made landfall in the mainland U.S. at Category 5 intensity: T​he most recent of these was Hurricane Michael in the Florida Panhandle in October 2018.

T​he others include Andrew in 1992 in South Florida, Camille in 1969 on the Mississippi Gulf Coast, and the 1935 Labor Day hurricane in the Florida Keys.

H​urricane Ian very nearly did that in 2022, but ticked down to a still-intense Category 4 hurricane when it made landfall.

Chris Dolce has been a senior meteorologist with weather.com for over 10 years after beginning his career with The Weather Channel in the early 2000s.

Jonathan Erdman is a senior meteorologist at weather.com and has been an incurable weather geek since a tornado narrowly missed his childhood home in Wisconsin at age 7. Reach out to him on X (formerly Twitter), Facebook and Threads.