How Unusual Is 10 Atlantic Hurricanes In One Season?

H​urricane season has been living up to its name this year with an overwhelming majority of the Atlantic's named storms hitting that intensity.

1​0 storms have now hit hurricane strength. Oscar's surprise intensification into a hurricane over the weekend notched the Atlantic's 10th hurricane out the 15 named storms that have formed this season. It's one of only 17 seasons on record, or since 1851, to have 10 or more hurricanes, according to meteorologist Steve Bowen.

O​ne caveat is that data prior to the era of satellite detection in 1966 is less certain when it comes to the exact intensity of storms, especially when they were located far from land.

Six years this century had 10 or more hurricanes. Most recently, the hyperactive 2020 season had 14 hurricanes, which is just behind the record of 15 set in 2005. 2010, 2012 and 2017 also had 10 or more storms reach hurricane strength, according to Bowen's post on X.

T​he Atlantic has averaged about seven hurricanes annually from 1991 to 2020.

Five of them – Beryl, Debby, Francine, Helene and Milton – made continental U.S. landfalls. Ernesto and Oscar affected multiple land areas in the Caribbean.

A​s previously discussed, warmer-than-average sea-surface temperatures have been abundant this year. That's a big driver for why a large number of storms strengthened into hurricanes in areas where the atmospheric environment has little wind shear and/or dry air.

T​wo have been Category 5 hurricanes. Beryl became the earliest Category 5 on record when it entered the Caribbean on July 1.

T​hat was followed by Milton's extreme rapid intensification to a Category 5 when it was over the southwest Gulf of Mexico in early October. Milton's 180-mph winds made it one of only nine other Atlantic hurricanes to hit that wind threshold or higher.

T​here have been only five other years since 1950 that have generated two or more Category 5 Atlantic hurricanes, according to Dr. Phil Klotzbach, a meteorologist at Colorado State University.

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.