The official Atlantic hurricane season runs from June through November, but occasionally storms form outside those months. September is the most common month for hurricanes making landfall in the U.S., followed by August and October, according to an analysis of 1851 to 2015 data by the National Oceanic and Atmospheric Administration. No hurricanes made U.S. landfall before June and after November during the period studied.
A tropical cyclone is a rotating low-pressure weather system that has organized thunderstorms but no fronts, according to the National Oceanic and Atmospheric Administration. Hurricanes are tropical cyclones which have sustained winds of 74 mph. At this point a hurricane reaches Category 1 on the Saffir-Simpson Hurricane Wind Scale, which has a range of 1 to 5, based on the hurricane's intensity at the time of landfall at the location experiencing the strongest winds. The scale provides examples of the type of damage and impacts in the United States associated with winds of the indicated intensity. It does not address the potential for other hurricane-related phenomena such as storm surge, rainfall-induced floods and tornadoes.
Colorado State University atmospheric scientist and Triple-I non-resident scholar, Dr. Philip Klotzbach, and his forecast team released a discussion of Atlantic basin hurricane activity for 2022 on December 9, 2021. CSU estimates there is a 40 percent chance that North Atlantic sea temperatures will be above average, and no El Niño occurs. Higher sea temperatures and lack of El Niño effects point to a higher-than-average season. For this level of probability, Dr. Klotzbach and CSU estimate 13-16 named storms, 6-8 hurricanes and 2-3 major hurricanes next season. CSU’s first formal forecast for the 2022 Atlantic season will be released on April 7.
Atlantic Basin: The 2021 Atlantic basin hurricane season was above normal, according to atmospheric scientist and Triple-I non-resident scholar, Dr. Philip Klotzbach, and his team. There were 21 named storms during the season, an extremely high number of storms. It will be remembered as the season of Hurricane Ida, which made landfall in central Louisiana as a Category 4 hurricane, bringing tremendous wind and storm surge damage to the central Gulf Coast as well as significant inland flooding to the mid-Atlantic.
The season produced seven hurricanes—Elsa, Grace, Henri, Ida, Larry, Nicholas and Sam. Four hurricanes—Grace, Ida, Larry and Sam—reached major hurricane status (Category 3 and above). Ida and Sam reached Category 4 status. 2021 trails only 2020, with 30 named storms and 2005, with 28 named storms, for most named storms in a single season. Storm averages for 1981 to 2020, which were developed and adopted in April 2021, are 14 named storms, seven hurricanes and three major hurricanes. The scientists cited warmer than normal sea surface temperatures across the tropical Atlantic and La Nin᷈a conditions during peak season as the major settings for the season.
Tropical storm Ana, the first storm of the 2021 Atlantic hurricane season, formed as a subtropical storm on May 22 and became a tropical storm the next day. Ana makes 2021 the seventh consecutive year to have a named storm form before the official start of the hurricane season on June 1, according to Colorado State University atmospheric scientist and Triple-I non-resident scholar, Dr. Philip Klotzbach. Ana dissipated by May 24 northeast of Bermuda, according to the National Hurricane Center. Tropical storm Bill formed on June 14 east of Cape Hatteras, North Carolina. The storm moved north and did not threaten land before it dissipated.
Claudette became a tropical storm on June 19 near New Orleans, Louisiana. It was the first named storm to make landfall in the United States and brought heavy rain and wind to Alabama where 14 people perished. After it weakened it regained tropical storm strength again on June 21 in North Carolina and continued into the western Atlantic before dissipating near Nantucket, Massachusetts. Danny became a tropical storm on June 28 near Charleston, South Carolina and made landfall north of Hilton Head. Danny moved west into central Georgia as a remnant, bringing rain and windy conditions.
Elsa became a tropical storm on July 1 southeast of the Windward Islands, the fifth named storm of the 2021 Atlantic hurricane season. Elsa is the earliest fifth named Atlantic storm on record, according to Dr. Philip Klotzbach, breaking the record set by Edouard in 2020. Elsa became a hurricane on July 2 near Barbados, the first hurricane of the 2021 season. After moving into the eastern Caribbean Sea, Elsa was downgraded to a tropical storm and made landfall in Cuba on July 5. Elsa regained hurricane strength on July 6 and moved along the west coast of Florida, bringing heavy rain and gusty wind and made landfall in Taylor County along the North Florida Gulf Coast as a tropical storm. Elsa tracked north and brought torrential rain to Georgia and the Carolinas. Continuing northeastward Elsa dumped heavy rainfall and produced flash and urban flooding in the Mid-Atlantic to New England states and made landfall along the coast of Long Island near Southampton on July 9 and later near Watch Hill, Rhode Island. Post-tropically Elsa moved off the northeast coast into Atlantic Canada. Catastrophe modeler Karen Clark & Company estimates that Elsa’s insured losses in the United States will be $240 million from privately insured wind and storm surge damage to residential, commercial, and industrial properties and automobiles.
After a quiet month, Tropical Storm Fred formed southwest of Puerto Rico on August 10 and made landfall on the Dominican Republic on August 11. Fred, the sixth storm of the 2021 hurricane season, weakened to a tropical depression after bringing heavy rainfall to the Dominican Republic and Haiti. The depression became largely disorganized and brought heavy rainfall to Cuba. Fred regained tropical storm status on August 15 over the eastern Gulf of Mexico and made landfall in northwest Florida on August 16 with heavy rain, wind and flooding. Fred weakened to a tropical depression on August 17 as it moved into Alabama, Georgia and North Carolina, bringing heavy rain and flooding. Fred then moved into Virginia and the Mid-Atlantic states, bringing heavy rain, flooding and tornadoes.
Tropical Storm Grace formed on August 14 east of the Leeward Islands and moved westward, passing south of Puerto Rico and bringing heavy rain. Grace brought heavy rain to Haiti and the Dominican Republic as a tropical depression on August 16, causing floods. By August 17 Grace strengthened into a tropical storm over Jamaica and became the second hurricane of the 2021 Atlantic hurricane season on August 18 west of Grand Cayman Island. Grace made landfall on the eastern Yucatan Peninsula of Mexico near Tulum as a Category 1 hurricane. Grace continued to the southwest Gulf of Mexico and became a Category 3 storm on August 20. Grace made a second landfall on mainland Mexico on August 21 as a major storm before dissipating later that day.
Henri, the eighth named storm of the 2021 Atlantic hurricane season, formed on August 16 southeast of Bermuda. According to Dr. Philip Klotzbach, eight or more named storms formed in the Atlantic Ocean by August 16 in only two years since 1966—2005 and 2020. Henri became the third hurricane of the season on August 21 in the Atlantic Ocean north of Bermuda and made landfall on the coast of Rhode Island as a tropical storm. Henri brought heavy rainfall to the northern Mid-Atlantic and southern New England states before dissipating on August 23. According to catastrophe modeler KCC, insured losses from Henri will reach $155 million excluding losses for the National Flood Insurance Program.
Ida became a tropical storm on August 26 in the Caribbean Sea and made landfall in Cuba on August 27. Ida reached hurricane status in the Gulf of Mexico and strengthened to a major Category 3 hurricane by August 29, the second major hurricane of the 2021 season. Ida made landfall in southeastern Louisiana near Port Fourchon as a Category 4 storm, bringing catastrophic storm surge, extreme winds of 150 mph and flash flooding. The storm made a second landfall that day southwest of Galliano, Louisiana. Ida passed to the west of New Orleans as a Category 2 storm and left more than 1 million homes and businesses in Louisiana and Mississippi without power. The entire city of New Orleans, where levees largely held, was without power and repairs took weeks to complete. Widespread cellphone failure also affected the city. The storm caused damage to about 94 percent of oil and gas production in offshore Gulf of Mexico facilities.
The storm was downgraded to a tropical storm on August 30, moving northwestward and bringing heavy rainfall to Mississippi, Alabama and the Florida Panhandle and to the Ohio Valley, Mid-Atlantic and Northeast states as a tropical depression. Ida was the second strongest hurricane to make landfall in Louisiana, tied with Laura in 2020 and the Last Island storm of 1856, according to Dr. Philip Klotzbach. Hurricane Katrina in 2005 remains the strongest hurricane to hit Louisiana, causing insured losses of $87 billion in 2020 dollars, including flood claims from the National Flood Insurance Program, according to Aon. Insured losses for Ida are forecast to reach $18 billion to $29.5 billion according to catastrophe modelers. An estimate from RMS, for $27.2 billion to $38 billion, includes insured losses across Ida’s entire track for onshore and offshore wind, surge and private flood losses. PCS/Verisk expects losses from Ida to rank as the third highest insured-loss hurricane, excluding NFIP losses, close behind Hurricane Irma of 2017. Final losses will take months to tally.
On August 29 and 30 Julian and Kate briefly became tropical storms but dissipated without threat to land. Larry became a hurricane on September 2 in the eastern tropical Atlantic. Larry, the 12th named storm of the 2021 season and the fifth hurricane, became a major (Category 3) hurricane on September 3. Larry marks the first time on record that the Atlantic has had more than 3 hurricane formations between 18 August and 2 September, according to Dr. Philip Klotzbach. Larry, a very large hurricane, moved westward towards Bermuda bringing tropical storm conditions and made landfall on Newfoundland on September 10.
Tropical Storm Mindy formed in the northeast Gulf of Mexico on September 8 and made landfall that day on St. Vincent Island, Florida. After passing over the Florida Panhandle, Mindy moved over southeastern Georgia and coastal South Carolina bringing heavy rainfall as a tropical depression.
Hurricane Nicholas, the sixth hurricane of the 2021 Atlantic hurricane season, formed on September 12 in the southeastern Gulf of Mexico and became a hurricane the next day as it approached the southern Texas coast. Nicholas made landfall on September 14 on the Texas coast near Sargent Beach, bringing heavy rain, high winds and dangerous surge. As a tropical storm, Nicholas moved north eastward over Houston and slowly moved eastward over southwest Louisiana where it dissipated, Nicholas brought heavy rain and flooding across coastal Texas and Louisiana. Catastrophe modeler KCC estimated that insured losses from Nicholas will total $950 million, excluding NFIP losses.
Hurricane Sam, the 18th named storm of the 2021 Atlantic hurricane season, formed on September 24 in the central tropical Atlantic and rapidly strengthened to Category 4 status on September 25 as it moved west in the central tropical Atlantic. Sam was the fourth major (Category 3 or higher) hurricane of the season. Sam, a very large, long-lived, intense hurricane, began to lose strength on October 2 after it passed southeast of Bermuda and moved northeastward over the open Atlantic. It became a powerful post-tropical cyclone over the far North Atlantic between Newfoundland and Iceland. Hurricane Sam is tied with Ida for the strongest sustained winds from a 2021 Atlantic hurricane to date, according to Dr. Philip Klotzbach.
In October, no major, Category 3 or higher, hurricanes formed. According to Dr. Klotzbach, this was the first time since 1977 that there were no major storms in October. Tropical storm Wanda, the 21st storm of the 2021 Atlantic hurricane season, formed on November 1 over the central Atlantic and dissipated on November 8. Dr. Klotzbach says that only two Atlantic hurricanes seasons have had more than 21 named storms, 2005, with 28 named storms, and 2020, with 30 named storms. There were no major storm formations in the Atlantic or Pacific since Hurricane Sam on September 25. Dr. Klotzbach noted that every other hurricane season in the satellite era (since 1966) have had at least two global major hurricane formations between September 26 and November 19.
Atlantic Basin: The record-breaking 2020 hurricane season produced 30 named storms. The old record was set in 2005 when there were 28 storms. Fourteen—Hanna, Isaias, Laura, Marco, Nana, Paulette, Sally, Teddy, Gamma, Delta, Epsilon, Zeta, Eta and Iota—became hurricanes. Seven—Laura, Teddy, Delta, Epsilon, Zeta, Eta and Iota—became major (Category 3 or stronger) storms. A typical year has 12 named storms, six hurricanes, and three major hurricanes. Since all 21 of the letters of the alphabet that meteorologists use were exhausted, they began using the Greek alphabet to name storms. A record-breaking eleven named storms or hurricanes made landfall in the continental United States. Of those, six hurricanes made landfall in the continental United States. The 2020 Atlantic hurricane season also broke records as Tropical Storm Edouard formed as the earliest 5th named Atlantic storm on record, according to Colorado State University atmospheric scientist and Triple-I non-resident scholar, Dr. Philip Klotzbach, and continued to shatter earliest storm records Zeta as the earliest 27th named storm. The season began early as Tropical Storm Arthur formed on May 16 in the Atlantic Ocean east of Florida, marking the sixth consecutive year that the hurricane season began before the traditional official beginning of the season on June 1. Tropical Storm Bertha, the second named storm to occur before the official beginning of the hurricane season, formed on May 27 near South Carolina. After making landfall near Charleston with winds of 50 mph, Bertha brought heavy rainfall in South Carolina, North Carolina and Virginia. According to Aon, 2020 is the third year since 1965 that two named storms developed in the Atlantic Ocean before the beginning of the hurricane season. The company said Bertha caused millions of dollars in insured losses.
Tropical Storm Cristobal formed on June 2 in the Gulf Coast of Mexico. After landfall in Mexico, it made landfall in southeast Louisiana on June 7 between the mouth of the Mississippi River and Grand Isle, Louisiana. Cristobal brought tropical storm-force winds to the Gulf Coast from southeastern Louisiana to the Florida Panhandle and traveled into Arkansas and eastern Missouri, eventually reaching the Great Lakes area and Ontario, Canada. Cristobal caused three direct deaths in the United States.
Tropical Storm Fay became the 6th named storm of the 2020 Atlantic hurricane season when it formed on July 9 off the coast of North Carolina. Fay made landfall on July 10 near Atlantic City, New Jersey, as tropical storm conditions and heavy rainfall spread northeastward along the Mid-Atlantic coast. According to catastrophe risk modeler Karen Clark & Company (KCC), insured losses for wind and storm surge damage to residential, commercial and industrial properties and automobiles in Maryland, Delaware, New Jersey, Pennsylvania and New York are estimated to total $400 million. Fay caused two direct deaths in the United States.
Hurricane Hanna, the first hurricane of the 2020 Atlantic hurricane season, developed on July 23 southeast of Corpus Christi, Texas, in the Gulf of Mexico. Hanna strengthened into a hurricane on July 25 and made landfall on Padre Island, Texas, north of Port Mansfield, as a strong Category 1 hurricane, and then had a second landfall in Kennedy County. Hanna brought hurricane conditions to south Texas as it moved inland and brought heavy rain and flash flooding over far southeast Texas and northeast Mexico. Rainfall totals in the areas were between 4 to 6 inches but some areas received a foot of rain. Insured losses in Texas range from $350 million to $400 million, according to catastrophe modelers KCC and RMS.
Hurricane Isaias became the second hurricane of the 2020 season on July 30, and caused flash flooding and high winds over Puerto Rico. After weakening to a tropical storm, Isaias brought winds and storm surge to East Coast Florida. Isaias regained hurricane strength and made landfall in North Carolina near Ocean Isle Beach as a Category 1 hurricane on August 3. As a tropical storm, Isaias moved north into Virginia, the Mid-Atlantic states and New England, bringing storm surge, dangerous winds and heavy rain before dissipating on August 5 in southeastern Canada. The storm caused 10 direct deaths in the United States, spawned tornadoes in five states and caused $2.7 billion in insured losses in the United States, the Caribbean and Canada, including flood losses in the United States from the National Flood Insurance Program (NFIP), according to Aon.
Tropical Storm Josephine formed in the tropical Atlantic Ocean on August 13 and dissipated without threatening land. Kyle formed northwest of New Jersey and dissipated in the North Atlantic.
Hurricane Laura formed on August 21 and brought heavy rain and flooding to islands in the Caribbean, including the Virgin Islands and Puerto Rico, before heading into the Gulf of Mexico. On August 24 Laura became the fourth hurricane of the 2020 Atlantic hurricane season northwest of Cuba, and the first major hurricane on August 26. Laura quickly intensified to a strong Category 4 storm and made landfall on August 27 near Cameron, Louisiana, close to the Texas-Louisiana border, bringing catastrophic storm surge, extreme wind and flash flooding. According to Dr. Klotzbach, Laura was the 7th named storm to make landfall in the continental U.S. in 2020, breaking the record of six recorded in 1886 and 1916. He also noted that Laura made landfall with 150 mph winds, stronger than Hurricane Katrina in 2005, and tied with the Last Island hurricane of 1856 as the strongest to strike Louisiana. Damaging winds and flooding rainfall spread inland over central and northern Louisiana and as a remnant of the storm traveled through the mid-Mississippi Valley it brought heavy rain to the Mid-Atlantic states. Laura was responsible for seven direct deaths in the United States and widespread property damage, especially in Lake Charles, Louisiana. By September 30, 2021, private insurers in Louisiana had paid or reserved $9.1 billion for 128,200 claims and insurers had closed 90 percent of all claims reported in Louisiana. Earlier estimates from Aon indicated that total insured losses in the United States and the Caribbean, including flood losses from the NFIP in the United States, would reach $10.0 billion.
Hurricane Marco formed in the northwest Caribbean near the Yucatan Peninsula of Mexico and became a hurricane on August 23 as it traveled northwest into the northern Gulf of Mexico. Marco made landfall in Louisiana near the mouth of the Mississippi River as a tropical storm on August 24 and weakened to a depression soon after.
Hurricane Paulette formed over the central tropical Atlantic on September 7. On September 12 it became a hurricane as it approached Bermuda. It made landfall on the island on September 14 and brought hurricane conditions and torrential rain. Paulette became a Category 2 storm later that day. Paulette caused two direct deaths in the United States.
Hurricane Sally became a hurricane on September 14 in the north central Gulf near the mouth of the Mississippi River. It made landfall as a slow-moving, Category 2 hurricane on September 16 near Gulf Shores, Alabama, bringing extremely dangerous, life-threatening storm surge and catastrophic, record-breaking rain to southern Alabama and the Florida Panhandle. Sally brought post-tropical conditions to Georgia, the Carolinas and southern Virginia. Total insured losses in the United States, including flood losses from the NFIP, totaled $3.5 billion, according to Aon. Sally caused four direct deaths in the United States.
Hurricane Teddy became a Category 4 hurricane on September 17 in the Western Atlantic. By September 23 Teddy brought destructive waves, strong wind and heavy rainfall to Atlantic Canada and made landfall in Nova Scotia. Teddy caused three direct deaths in the United States.
Hurricane Teddy formed on September 14 west of the Cabo Verde Islands and became a Category 2 hurricane on September 16 east of the Lesser Antilles. Teddy became a Category 4 hurricane on September 17 in the Western Atlantic. The hurricane turned northwestward and passed east of Bermuda as a Category 1 storm and continued north to Nova Scotia, becoming a Category 2 storm. By September 23 Teddy brought destructive waves, strong wind and heavy rainfall to Atlantic Canada and made landfall in Nova Scotia. Teddy caused three direct deaths in the United States.
Tropical storm Vicky also developed on September 14, west of the Cabo Verde Islands and dissipated a few days later. Wilfred became a tropical storm on September 18 in the eastern tropical Atlantic and did not threaten land before degenerating on September 20.
Tropical Storm Beta formed on September 18 in the Gulf of Mexico and brought tropical storm conditions to the southeastern coast of Texas on September 21 and made landfall there on September 21. The storm stalled inland in Texas before moving northeastward and deteriorating to a tropical depression. Beta dropped up to 20 inches of rain in parts of Texas, including about 14 inches in the Houston metropolitan area, and continued to bring heavy rain to Louisiana, Mississippi and Tennessee. According to Dr. Philip Klotzbach it was the 9th named storm to make landfall in the continental United States, tying the record set in 1916, and only the second time a letter from the Greek alphabet has had to be used by U.S. forecasters since the 1950s. Beta caused one direct death in the United States.
Hurricane Delta, the earliest 25th named storm on record, formed on October 5 in the Caribbean Sea near Jamaica and became the ninth hurricane of 2020 later that day. Delta rapidly intensified near the Yucatan Peninsula to Category 4 strength and made landfall there on October 7 as a Category 2 storm. Delta moved into the southern Gulf of Mexico and strengthened to a Category 3 storm on October 8. Delta made landfall as a Category 2 storm on the Louisiana coast near Creole on October 9, close to Hurricane Laura’s landfall site, and damaged areas already hit by Laura. Delta brought hurricane conditions to southwest and central Louisiana and eastern Texas before moving northeastward through Arkansas, Mississippi, and Alabama and the Tennessee valley as a tropical storm and later affecting the Mid-Atlantic states. As of September 30, 2021, private insurers in Louisiana had paid or reserved about $875.5 million for 56,600 claims. Insurers have closed 93 percent of all claims reported in Louisiana. Delta caused two direct deaths in the United States.
Hurricane Epsilon became a hurricane on October 20 and reached Category 3 status on October 21. Epsilon caused one direct death in the United States. Hurricane Zeta became a hurricane on October 26 and made landfall on the Yucatan Peninsula of Mexico. Zeta made landfall on October 28 as a Category 3 hurricane near Cocodrie, Louisiana and was the record-breaking fifth named storm to strike Louisiana in one season. Zeta brought storm surge, high winds and heavy rain to southeastern Louisiana and southern Mississippi and continued through the southeastern states with damaging winds and heavy rainfall. Zeta left about 2.6 million people without power across seven states. Louisiana Gov. John Bel Edwards said the hurricane caused catastrophic damage on Grand Isle in Jefferson Parish by causing three breaches in a levee. As of September 30, 2021, private insurers in Louisiana had paid or reserved about $629 million for 33,800 claims and insurers had closed 94 percent of all claims reported in Louisiana. Zeta caused five direct deaths in the United States and caused $2.3 billion in insured losses in the United States, including flood losses from the NFIP, and the Caribbean, according to Aon.
Hurricane Eta formed over the central Caribbean Sea on October 31 and became a Category 4 hurricane on November 2. On November 3 slow-moving Eta made landfall in Nicaragua as a Category 4 storm, bringing catastrophic wind damage, flash flooding, storm surge and landslides. Eta deteriorated over Honduras on its way to the north Caribbean Sea, but regained tropical storm strength and made landfall in Cuba on November 8. The storm turned northwestward and made landfall in Lower Matecumbe Key, Florida on November 8 as a strong tropical storm and continued to the southwest coast of Florida, bringing heavy rainfall, flash flooding and wind. Eta traveled into the Gulf of Mexico and regained hurricane status on November 11 offshore of southwestern Florida bringing heavy squalls with tropical-storm force winds. On November 12 Eta made a second landfall in Florida near Cedar Key as a tropical storm, producing dangerous storm surge, heavy rains and gusty winds along the Florida Gulf Coast and the northern Florida Peninsula. The storm then moved into the Atlantic Ocean near the Florida/Georgia border. Eta passed offshore of the coasts of South and North Carolina before dissipating. Eta caused seven direct deaths in the United States.
On November 10, a record-breaking 29th named storm—Theta—formed in the northeast Atlantic Ocean. Theta did not threaten land. Hurricane Iota, the 30th named storm of the 2020 hurricane season, became a hurricane on November 15 and became a major hurricane strengthening to Category 5 status on its way to Central America, and was the strongest hurricane of the 2020 hurricane season. The storm made landfall on the northeast coast of Nicaragua as a Category 4 storm on November 16, about 15 miles south of Hurricane Eta’s Category 4 landfall site on November 3.
East Pacific: Hurricane Douglas formed in the East Pacific on July 20 and became a hurricane on July 22. By July 23 Douglas was a Category 4 storm, heading toward the Hawaiian Islands. By mid-day July 26 Douglas was closing in on the island of Maui as a Category 1 hurricane. Douglas passed to the north of the islands of Maui, Oahu and Kauai, producing large swells, damaging surf, strong damaging winds. Rainfall between three and six inches but possibly more fell on the islands.
2019: The 2019 season yielded 18 named storms, six of which became hurricanes, including three major ones (Category 3 or higher, with maximum sustained winds of at least 111 mph.) Barry became a hurricane on July 13 in the Gulf of Mexico as it moved toward the Louisiana coast. It made landfall later that day near Intracoastal City, Louisiana, as a tropical storm, bringing heavy rain and wind to the north central Gulf Coast, and remained over Louisiana as it weakened into a tropical depression on July 14. Other areas impacted were the Mississippi River Valley and the southeastern states of Alabama, Florida and Mississippi.
Dorian became a hurricane on August 28 near St. Thomas, U.S. Virgin Islands. By August 30, Dorian had strengthened to a Category 4 storm and became an historic Category 5 storm on September 1 as it made landfall over the Abaco Islands in the Bahamas and Grand Bahama Island. Dorian continued to pound the Bahamas into September 3 with devastating wind, rain and storm surge. Dorian brought storm surge resulting in beach erosion and flooding to east coast Florida as a Category 3 storm, and later affected South and North Carolina. On September 6 Dorian made landfall at Cape Hatteras, North Carolina, as a Category 1 storm, bringing wind, storm surge and flooding to North Carolina and Virginia on its way north. It made landfall over Nova Scotia on September 7 as a Category 1 hurricane. Aon estimates industry insured losses in the United States from Dorian to total $3.5 billion, including reinsurance and NFIP losses.
Humberto became a hurricane on September 15 southwest of Bermuda and peaked at Category 3 as it approached the island on September 16. As a post-tropical storm Humberto produced large swells and rip tides along the east coast of the United States. Tropical Storm Imelda brought an estimated 16 to 24 inches of rain to Beaumont and Houston, Texas and heavy rain over a large section between southwestern Louisiana and Texas by September 20. Aon estimated that Imelda caused $1.2 billion in insured losses, including NFIP flood claims. Hurricane Jerry formed around the same time, becoming a hurricane on September 19. Hurricane Lorenzo became a Category 5 hurricane in the central subtropical Atlantic—the farthest east Category 5 Atlantic hurricane on record. It generated 49-foot waves, with an occasional rogue wave nearing 100 feet, sending swells to both sides of the Atlantic.
2018: During the 2018 Atlantic hurricane season 15 named storms formed. Eight of those storms became hurricanes and two of those, Florence and Michael, became major storms, Category 3 and above. Florence, the third hurricane of the season, reached Category 4 status as a slow-moving storm that brought hurricane-force winds, life-threatening storm surge, and freshwater flooding. Florence made landfall along the southeastern coast of North Carolina as a Category 1 storm and brought significant storm surge flooding to portions of eastern North Carolina. It produced rainfall that exceeded 20 inches along the North and South Carolina border, and in some parts of North Carolina exceeded 30 inches, a state record. The previous record was 24 inches caused by Hurricane Floyd in 1999. In South Carolina a new record was reached when rainfall reached almost 24 inches. Florence directly caused 22 deaths in the United States, including 15 in North Carolina, four in South Carolina and three in Virginia, according to the National Hurricane Center (NHC). Catastrophe modelers have estimated that insured losses from Hurricane Florence would range from $2.0 billion to $5.5 billion, excluding National Flood Insurance Program losses.
Hurricane Michael became a strong Category 5 storm on October 10 and made landfall near Mexico Beach, Florida, in the Florida Panhandle. Hurricane Michael was the strongest hurricane ever to hit the Florida Panhandle and the second known Category 5 landfall on the northern Gulf Coast, according to the National Oceanic and Atmospheric Administration. It was the first Category 5 storm to make landfall in the United States, after Hurricane Andrew in 1992. Michael caused 16 deaths in the United States: seven in Florida, five in Virginia, three in North Carolina and one in Georgia. Aon estimates that insured losses from Hurricane Michael, including losses covered by the federally administered National Flood Insurance Program, totaled $13.3 billion in dollars when it occurred and $13.6 billion in 2020 dollars, making it the ninth-costliest hurricane to hit the United States.
2017: The Atlantic hurricane season of 2017 broke several records, as 17 tropical storms formed, with 10 of them becoming hurricanes. Six hurricanes became major storms, Category 3 and above—Harvey, Irma, Jose, Lee, Maria and Ophelia. Two hurricanes, Irma and Maria, reached Category 5 strength. The 2017 Atlantic hurricane season was the first time three Category 4 hurricanes—Harvey, Irma and Maria—made landfall in the United States and its territories in one year, according to the Triple-I.
The chart below shows insured losses in dollars for the top 10 costliest hurricanes in the United States when they occurred and in 2020 dollars, adjusted for inflation. According to Aon, Katrina was the costliest hurricane on record, causing $65 billion in insured losses when it occurred in 2005, including losses from the NFIP. Losses from Katrina totaled $86.6 billion in 2020 dollars.