Why 'I' Hurricanes Have Been Most Notorious This Century | Weather.com

Beware the 'I': 11 Atlantic Hurricanes Starting With 'I' Have Been Retired This Century

Have you noticed how many hurricanes starting with the letter "I" have been terribly destructive lately? It turns out there's a simple explanation.

Play

Tropical Wave To Develop As It Moves West

Imelda is the name that's up in the 2025 Atlantic hurricane season, and so far this century, storms beginning with "I" have often been the most damaging.

Eleven "I" hurricanes retired: In the past 24 years, 11 other I-hurricanes have had their names retired by the World Meteorological Organization. This is done when a particular tropical storm or hurricane is so deadly and/or damaging that future use might be considered insensitive or confusing.

(Further beef up your forecast with our detailed, hour-by-hour breakdown for the next 8 days – only available on our Premium Pro experience.)

Tracks and locations of retired hurricanes starting with the letter "I" from 2001 through 2024.
(Data: NOAA/NHC)

The notorious "I" list: It began with four straight I-hurricanes from 2001 through 2004 and ended with two more retirees this decade.

- Ian 2022: Florida's costliest hurricane and its aftermath claimed at least 150 lives

- Ida 2021: Storm surge and rainfall flooding in Louisiana, then flash flooding in the Northeast

- Irma 2017: Carved a destructive path from the northeast Caribbean Islands to Florida

- Ingrid 2013: Triggered deadly flooding and mudslides (in addition to eastern Pacific Manuel) in Mexico

- Irene 2011: While a close call for storm surge in New York City (later smashed by Superstorm Sandy), catastrophic flooding resulted in parts of Vermont, New York and Pennsylvania

- Igor 2010: The most damaging hurricane in recent history for Newfoundland; also struck Bermuda

- Ike 2008: Massive storm surge on the upper Texas and Louisiana coasts; a high wind event well inland to Ohio Valley and beyond

- Ivan 2004: Devastated Grand Cayman; 10- to 15-foot surge along the U.S. Gulf Coast; 120 tornadoes in U.S.

- Isabel 2003: One of most significant hurricanes to hit eastern Virginia since Hazel (1954); storm surge pushed up Chesapeake Bay

- Isidore 2002: Heavy damage to agricultural interests in western Cuba and Mexico's Yucatan Peninsula

- Iris 2001: Devastated southern Belize as a Category 4 hurricane

(For even more granular weather data tracking in your area, view your 15-minute details forecast in our Premium Pro experience.)

Hurricane Ian slammed ashore in southwest Florida at Category 4 intensity on Sept. 28, 2022. Its peak surge of over 15 feet and wind gusts to 140 mph leveled much of Fort Myers Beach and Sanibel Island. Ian produced record inland flooding in the Florida Peninsula, including near Orlando, that would last for weeks. Ian was the costliest hurricane on record to hit Florida. Ian later made a second landfall in South Carolina, spreading storm surge and high winds from northeast Florida to the Carolinas. (AP Photo/Wilfredo Lee)
Hurricane Ian slammed ashore in southwest Florida at Category 4 intensity on Sept. 28, 2022.
(AP Photo/Wilfredo Lee)
Advertisement

"I" leads the pack: Since 1953, when the naming of Atlantic tropical cyclones ditched the phonetic alphabet, 99 Atlantic tropical cyclone names have been retired.

Thirteen retired names start with "I," the most of any letter. Inez (1966) and Ione (1955) were the other two retired "I" hurricanes.

The number of retired Atlantic hurricane names by their starting letter from 1954 through 2024. Two hurricanes with Greek letter names were also retired in 2020, though Greek letter names are no longer used in supplemental name lists.
(Data: NOAA/NHC)

While Iota was also retired in 2020 due to its impact in Central America, that name was only utilized because the 2020 name list was used up, requiring the use of the Greek alphabet after Wilfred.

Other impactful "I" storms: Similar to athletes that had good careers but didn't have their jersey numbers retired, there have also been other recent "I" storms that were damaging, but not to the extent that their names were retired.

Hurricane Idalia in 2023 brought feet of storm surge, heavy rain and strong winds in a Category 3 landfall in northern Florida's Gulf Coast.

Hurricane Isaias in 2020 tore through the East with destructive winds after its North Carolina landfall.

Tropical Storm Imelda in 2019 dumped over 40 inches of rain near the upper Texas coast, leading to massive flooding just two years after Hurricane Harvey.

Vehicles are seen on a flooded road in Houston, Texas, on Thursday, Sept. 19, 2019. (Aimee Gardner)
Vehicles are seen on a flooded road in Houston, Texas, on Thursday, Sept. 19, 2019, during Tropical Storm Imelda.
(Aimee Gardner)

The secret behind "I": The Atlantic Basin has generated an average of 14 named storms each hurricane season from 1991 through 2020.

Since "I" is the ninth letter of the alphabet, and thus the ninth named storm of the season, you can pretty much count on an "I" storm each season now, as opposed to, say, the 1970s or 1980s, when named storm counts were lower. (Note: A long-term reanalysis project at NOAA's Hurricane Research Division has added a number of unnamed storms in past decades that would have earned an "I" name if they were detected at the time.)

According to the National Hurricane Center, the average date the ninth storm developed over the past 30 years is Sept. 16.

That date is in the heart of hurricane season, when tropical easterly waves coming off western Africa are most vigorous; shearing winds that could rip apart a developing tropical system in the zone between Africa and the Lesser Antilles are lowest; and sea-surface temperatures are at their warmest.

In a typical year, an "I" storm has a better chance to be a long-lived, intense hurricane with these generally favorable factors in play.

Earliest (red arrow), average (white arrow) and latest (blue arrow) dates when an "I" storm first became a tropical storm from 1966-2024, with a graph of average named storm frequency in the Atlantic Basin. Note: only 39 of the 59 seasons in that period had an "I" storm.

Not a guarantee: That doesn't mean every year will generate a terrible I-storm.

In 2024, Hurricane Isaac was a classic North Atlantic "fish storm" that never threatened land.

Despite the overall historic 2005 hurricane season, its I-storm — Hurricane Irene — remained out in the open Atlantic.

So, don't fixate on this statistic. Be prepared for any storm or hurricane threat throughout the season. Even if it doesn't start with "I".

Jonathan Erdman is a senior meteorologist at weather.com and has been covering national and international weather since 1996. His lifelong love of meteorology began with a close encounter with a tornado as a child in Wisconsin. Extreme and bizarre weather are his favorite topics. Reach out to him on X (formerly Twitter), Threads, Facebook and Bluesky.

Advertisement