The Atlantic hurricane season officially began on June 1, with the first tropical cyclone developing on June 24. Although 23 tropical depressions developed, only nine of them reached tropical storm intensity; this was near normal compared to the 1950–2000 average of 9.6 named storms. Six of these reached hurricane status, slightly above the 1950–2000 average of 5.9. Furthermore, three storms reached major hurricane status; above the average 1950–2000 average of 2.3. Collectively, the cyclones of this season caused at least 84 deaths and over $564.7 million in damage. The Atlantic hurricane season officially ended on November 30, though the final tropical cyclone became extratropical on December 13.
Tropical cyclogenesis began in June, with the development of a tropical depression on June 24, followed by Tropical Storm Amy on June 27. Four systems originated in July, including Hurricane Blanche. After Tropical Depression Six dissipated on July 30, tropical activity went dormant for over three weeks, ending with the development of Hurricane Caroline on August 24. Another cyclone, Hurricane Doris, also formed in August. September was the most active month of the season, featuring eight tropical cyclones, including hurricanes Eloise, Faye, and Gladys. In October, four systems formed, one of which intensified into Tropical Storm Hallie. Two tropical depressions developed in November. The last system, a subtropical storm, formed on December 6 and transitioned into an extratropical cyclone on December 13.
The season's activity was reflected with an accumulated cyclone energy (ACE) rating of 76. Broadly speaking, ACE is a measure of the power of a tropical or subtropical storm multiplied by the length of time it existed. Therefore, a storm with a longer duration, such as Humberto, will have high values of ACE. It is only calculated for full advisories on specific tropical and subtropical systems reaching or exceeding wind speeds of 39 mph (63 km/h). Accordingly, tropical depressions are not included here. After the storm has dissipated, typically after the end of the season, the NHC reexamines the data, and produces a final report on each storm. These revisions can lead to a revised ACE total either upward or downward compared to the operational value.
A trough of low pressure developed into a tropical depression while just north of Grand Bahama on June 27. The depression headed generally northward and remained weak. Upon nearing the coast of the Carolinas, the depression turned sharply eastward ahead of a rapidly approaching trough. Early on June 29, the system intensified into Tropical Storm Amy offshore North Carolina. Further intensification and the storm reached its peak intensity with winds of 70 mph (110 km/h) and a barometric pressure of 981 mbar (hPa; 28.97 inHg) by July 2. During most of the storm's existence, Amy featured many subtropical characteristics but was not classified as such due to the proximity to land. By July 4, the system moved southeast of Newfoundland before becoming extratropical.
The main effects from Amy were rough seas, reaching up to 15 ft (4.6 m) in height, that were felt from North Carolina to New Jersey, inflicting minor coastal flooding and beach erosion. The storm also brought generally light rainfall to land, peaking at 5.87 in (149 mm) in Belhaven, North Carolina. Offshore North Carolina, a schooner carrying four people capsized on June 30, resulting in the death of the father of the other three crew members. They remained at sea for roughly 15 days before being rescued by a Greek merchant ship.
A tropical wave emerged into the Atlantic Ocean from the west coast of Africa on July 14. The system remained weak for about a week, before convection began increasing significantly on July 21. After wind shear decreased, the wave managed to develop into a tropical depression on July 24 about 355 miles (570 km) northeast of the Turks and Caicos Islands. It moved northwestward until early on July 26, when an approaching cold front and associated trough caused the depression to turn northeastward. Around that time, the cyclone intensified into Tropical Storm Blanche. Because the cold front weakened and baroclinity, Blanche continued to intensify, becoming a Category 1 hurricane on July 27. Slightly further deepening occurred, with the storm peaking with winds of 85 mph (140 km/h) and a minimum barometric pressure of 980 mbar (29 inHg). Before 12:00 UTC on July 28, Blanche made landfall in Barrington, Nova Scotia, with winds of 80 mph (130 km/h). The system quickly transitioned into an extratropical cyclone, which soon dissipated.
In Atlantic Canada, the remnants of Blanche produced high winds, gusting up to 70 mph (110 km/h) and moderate rainfall, peaking at 3.1 in (79 mm) in Chatham, New Brunswick. The strong winds knocked over two mobile homes and destroyed a slaughterhouse, which was under construction. Additionally, trees and power lines were downed, leaving between 500 and 1,000 customers without electricity. The electrical corporation in Nova Scotia suffered about $196,600 in damage. Telephone services were also interrupted. The A. Murray MacKay Bridge was closed after an oil rig broke loose and threatened to strike the bridge. In Prince Edward Island, flights to and from the Charlottetown Airport were canceled, as was ferry service to Nova Scotia. Many homes and businesses lost telephone service. Overall, damage in Canada reached about $6.2 million.
On July 24, the fifth tropical depression of the season formed over the southwestern Gulf of Mexico. Deep convection associated with the system persisted around the center of circulation. Forecasters at the time anticipated the depression to intensify into a tropical storm before moving over land. Not long after forming, the depression made landfall in Tampico, Mexico at peak intensity; a barometric pressure of 1007 mbar (hPa; 29.74 inHg) was recorded in the city with sustained winds of 37 mph (60 km/h). Just prior to this, an air force reconnaissance mission into the cyclone found 50 mph (85 km/h) winds; however, due to the interaction with land, the NHC did not upgrade the depression. The system was no longer monitored by the NHC after landfall.
Tropical Depression Four developed from a trough of low pressure in the northeastern Gulf of Mexico about 60 mi (95 km) southwest of Cape San Blas, Florida, on July 27. The depression moved west-northwestward and strengthened slightly to reach winds of 35 mph (55 km/h), but remained below tropical storm intensity and made landfall in eastern Louisiana. Once inland, the depression slowly weakened and re-curved northwestward on July 30 into Mississippi. Around that time, the depression dissipated. The remnants persisted at least until August 3, at which time it was situated over Arkansas.
The tropical depression dropped heavy rainfall, with some areas of the Florida Panhandle experiencing more than 20 in (510 mm) of precipitation. Bay, Gulf, Holmes, Okaloosa, Santa Rosa, Wakulla, and Walton were hardest hit. Numerous roads were flooded and closed, with $3.2 million in damage incurred to that infrastructure. About 500 homes suffered flood damage, 22 of which were destroyed. Damage is estimated to have reached $8.5 million in the state of Florida alone. In southern Alabama, overflowing rivers flooded several businesses and homes in Brewton and East Brewton. Damage in Alabama totaled approximately $300,000.
A tropical wave that emerged into the Atlantic from the west coast of Africa on August 15 developed into a tropical depression about 200 mi (320 km) north of Hispaniola on August 24. The depression moved west-southwestward and failed to intensify before crossing the Turks and Caicos Islands and making landfall near Mayarí, Holguín Province, in Cuba on August 25. After emerging into the Caribbean Sea, the cyclone headed west-northwestward beginning on August 27. By the following day, the depression entered into the Gulf of Mexico after passing just offshore the Yucatán Peninsula. The system then intensified into Tropical Storm Caroline early on August 29. At 00:00 UTC on August 30, Caroline intensified into a hurricane. Further strengthening occurred, with the storm peaked as a Category 3 hurricane with winds of 115 mph (185 km/h) and a minimum pressure of 963 mbar (28.4 inHg) about 24 hours later. Around that time, Caroline made landfall in a rural area of Tamaulipas. The system rapidly weakened and dissipated on September 1.
In Mexico, the storm produced 10 ft (3 m) storm tides along the coast, while 5-10 in (127–254 mm) of rain fell inland. The rainfalls caused flooding, which forced 1,000 people to evacuate and left moderate damage to homes and businesses. The precipitation ended an eight-month drought that was affecting inland portions of northern Mexico and decreasing the area's corn production. Along the coast, several small villages sustained significant damage from the hurricane's storm surge. Portions of south Texas also experienced heavy rainfall, with 11.93 in (303 mm) at Port Isabel. Brownsville broke a record for the highest amount of precipitation observed on a day in August. Two deaths occurred from drowning in Galveston.
A low pressure area developed within a frontal band over the central Atlantic on August 27. At 12:00 UTC on the following day, the system developed into a subtropical storm while situated 930 mi (1,500 km) southwest of Flores Island in the Azores. The subtropical classification was due to no central dense overcast (CDO), with the showers and thunderstorms mainly consisting of a strong band of convention located southeast of the center, as well as its association to the frontal band. Because the system was out of the authorized range of reconnaissance aircraft flights, satellites and ships were used to monitor the storm's intensity and tropical status. After satellite imagery indicated that the system became more symmetrical, developed CDO, and detached from the frontal system, the cyclone was reclassified as Tropical Storm Doris on August 29.
Doris made meteorological history when, on August 31, it became the first Atlantic hurricane ever to be upgraded to hurricane intensity solely on the basis of satellite pictures, via the Dvorak technique. The cyclone then curved northward and intensified further during the next few days, becoming a Category 2 hurricane early on September 2. Based on the Dvorak technique, it is estimated that Doris peaked with maximum sustained winds of 110 mph (175 km/h) and a minimum barometric pressure of 965 mbar (28.5 inHg) shortly thereafter. By September 3, the hurricane began interaction with a non-tropical low pressure. On the following day, Doris quickly weakening to a tropical storm and transitioned into an extratropical cyclone about 830 mi (1,340 km) south-southeast of Cape Race, Newfoundland, around 06:00 UTC.
A tropical wave developed into a tropical depression on September 13 to the east of the Virgin Islands. The system tracked westward and strengthened into Tropical Storm Eloise while passing to the north of Puerto Rico. Eloise briefly reached hurricane intensity soon thereafter, but weakened back to a tropical storm around landfall over Hispaniola. The cyclone emerged into open waters of the northern Caribbean Sea. After striking the northern Yucatán Peninsula, Eloise turned northward and re-intensified. In the Gulf of Mexico, the cyclone quickly deepened, becoming a Category 3 hurricane on September 23. The hurricane made landfall west of Panama City, Florida, before moving inland across Alabama and dissipating on September 24.
The storm produced heavy rainfall throughout Puerto Rico and Hispaniola, causing extensive flooding that left severe damage 59 fatalities. Thousands of people in these areas became homeless as flood waters submerged numerous communities. As Eloise progressed westward, it affected Cuba to a lesser extent. In advance of the storm, about 100,000 residents evacuated from the Gulf Coast region. Upon making landfall in Florida, Eloise generated wind gusts of 155 mph (249 km/h), which demolished hundreds of buildings in the area. The storm's severe winds, waves, and storm surge left numerous beaches, piers, and other coastal structures heavily impaired.
Wind-related damage extended into inland Alabama and Georgia. Further north, torrential rains along the entire East Coast of the United States created an unprecedented and far-reaching flooding event, especially into the Mid-Atlantic States. In that region, an additional 17 people died as a result of freshwater flooding from the post-tropical storm; infrastructural and geological effects were comparable to those from Hurricane Agnes three years prior. Across the United States, damage amounted to approximately $560 million. The storm killed 80 people along its entire track.
A tropical wave emerged into the Atlantic from the west coast of Africa on September 14. After detaching from the Intertropical Convergence Zone (ITCZ) on September 18, the wave quickly developed into a tropical depression about 575 mi (925 km) west of the Cabo Verde Islands. Moving northwestward, the depression intensified according to ships and satellite imagery, becoming Tropical Storm Faye on September 19. The cyclone then moved westward and was unable to intensify further due to increasing wind shear, before weakening to a tropical depression on September 23. Shortly thereafter, Faye turned to the north, crossing an upper trough axis over the central Atlantic. Southwesterly flow aloft allowed the system to re-strengthen, with Faye becoming a tropical storm again on September 25. Faye accelerated to the northwest and deepened into a Category 1 hurricane early on September 26, several hours before reaching Category 2 intensity.
Around 23:00 UTC on September 26, the cyclone passed about 35 mi (56 km) east of Bermuda. winds up to 69 mph (111 km/h) and heavy rains were recorded on the island. Up to 2.8 in (71 mm) of rain fell in Bermuda from the hurricane. Already severely impacted by flooding from Eloise days earlier, New England prepared for additional flooding from Faye. The National Weather Service issued flash flood watches, resulting in more evacuations. At 00:00 UTC on September 27, the hurricane reached its maximum sustained wind speed of 105 mph (165 km/h). Later that day, Faye curved northeast under strong westerly flow. Although the system weakened to a Category 1 hurricane late on September 28, the storm reached its minimum barometric pressure of 977 mbar (28.9 inHg), observed by a reconnaissance aircraft. Faye then curved eastward and lost tropical characteristics, becoming extratropical at 12:00 UTC on September 29, while situated northwest of Corvo Island in the Azores.
A tropical wave emerged into the Atlantic from the west coast of Africa on September 17. The system developed into a tropical depression while several hundred miles southwest of Cape Verde on September 22. Initially, the depression remained weak, but after encountering warm sea surface temperatures and low wind shear, it became Tropical Storm Gladys on September 24. The storm then entered a more unfavorable environment, but on September 28, Gladys became a Category 1 hurricane. Shortly thereafter, the storm reentered an area favorable for strengthening. Eventually, a well-defined eye became visible on satellite imagery.
As the storm tracked to the east of the Bahamas, a curve to the north began, at which time an anticyclone developed atop the cyclone. This subsequently allowed Gladys to rapidly intensify into a Category 4 hurricane, reaching maximum sustained winds of 140 mph (230 km/h) on October 2. Thereafter, Gladys began to weaken and passed very close to Cape Race, Newfoundland before merging with a large extratropical cyclone the next day. Effects from the system along the East Coast of the United States were minimal, although heavy rainfall and rough seas were reported. In Newfoundland, strong winds and light precipitation were observed.
A tropical depression formed in the southern Gulf of Mexico on October 14. Rounding the western periphery of the subtropical ridge, the depression strengthened while moving northeast towards the central Gulf coast ahead of an advancing cold front. Moving inland late on October 16, the depression became an extratropical cyclone as it through the Southeast and Mid-Atlantic states, before moving offshore New England. Heavy rains fell along the frontal boundary ahead of the system, leading to flooding across eastern Louisiana, central Mississippi, the western Florida panhandle, central Tennessee, western Virginia, and eastern New York.
The heavy rains which fell upon Jackson, Mississippi established a new daily rainfall record for October 16 and a new 24-hour rainfall record for the month of October. Eight bridges were damaged across Jackson County, Tennessee due to the floods. Heavy rains led to extensive damage to the soybean and corn crops in Hickman and Marion counties in Tennessee. Six tornadoes touched down in association with this system, with two reported in Alabama, two across northwest Florida, and two across North Carolina. One died due to flooding in Mississippi.
A frontal trough exited the East Coast of the United States on October 18. The southern portion of the system became stationary near the Bahamas; simultaneously, a cut-off upper-level low formed in the same region. The disturbance produced scattered convection, until a tropical wave merged with it on October 23. The system developed into a subtropical depression by October 24, while located about 100 mi (160 km) east of Daytona Beach, Florida. The depression drifted northward on October 25 and eventually acquired tropical characteristics by October 26. Due to tropical storm force winds, the system was reclassified as Tropical Storm Hallie, while situated about 100 mi (160 km) east of Charleston, South Carolina. Hallie accelerated to the northeast starting on October 26. By the following day, Hallie peaked with winds of 50 mph (85 km/h). Later that day, Hallie merged with a frontal zone and became extratropical offshore Virginia.
The precursor to Hallie produced extensive cloudiness precipitation in the Bahamas. On October 27, gale warnings were issued for portions of the Outer Banks of North Carolina, and small craft advisories were posted for coastal areas from Georgia to Virginia. Tides along the North Carolina and Virginia coasts were generally between 1 and 2 ft (0.30 and 0.61 m) above normal. Generally light precipitation fell, peaking at 2.55 in (65 mm) in Manteo, North Carolina. Additionally, the pressure gradient between Hallie and a high pressure area increased winds across much of the East Coast of the United States. However, because the storm remained primarily offshore, damage was minimal, and no fatalities were reported.
An extratropical low pressure system developed into a subtropical storm about 615 mi (990 km) east-southeast of Cape Race, Newfoundland, at 12:00 UTC on December 9. The storm moved rapidly southward and intensified, reaching maximum sustained winds of 70 mph (110 km/h) about 24 hours later. Shortly thereafter, sustained winds began decreasing. However, late on December 11, the storm attained its minimum barometric pressure of 985 mbar (29.1 inHg). The system began moving southeastward and then eastward. By 12:00 UTC on December 12, the cyclone weakened to a subtropical depression. Moving northward, it dissipated 24 hours later while situated about 505 mi (815 km) south-southwest of Flores Island in the Azores.
In addition to the named storms and notable tropical depressions, several other minor tropical depression developed during the season. On June 24, the first tropical depression developed over the central Atlantic. It tracked westward for two days, before executing a counter-clockwise loop. By June 28, the system had completed the loop and was tracking north. The depression dissipated about 305 miles (491 km) southeast of Sable Island on June 29. A third tropical depression formed northeast of the Bahamas on July 4. Tracking northeastward, the system did not intensify and was last noted over open waters midday on July 5.
On September 3, a tropical depression developed near Cape Verde. Generally tracking west, the depression eventually dissipated near the Lesser Antilles on September 9. Another tropical depression developed near west coast of Africa on September 3. It moved generally westward and dissipated on September 6. Tropical Depression Seven formed on September 5, in the southwestern Gulf of Mexico. Tracking west-northwestward, the system nearly attained tropical storm-status; however, it made landfall later that day near Tampico, Mexico and dissipated not long after. Another tropical depression developed near Bermuda on September 11. Initially, the depression drifted northeastward but later accelerated and dissipated by September 14.
Tropical Depression Eleven developed near the Gulf of Honduras on September 25 and tracked slowly westward. By September 28, the depression made landfall in northern Belize before dissipating two days later. A tropical depression developed over the eastern Atlantic Ocean on October 3. It dissipated by October 5. Tropical Depression formed on October 27 over the southwestern Caribbean Sea and tracked northwest. After turning nearly due west, the depression briefly made landfall near the Nicaragua–Honduras border and made another landfall in southern Belize shortly before dissipating on October 29.
On November 8, a tropical depression developed off the coast of Honduras. Moving north-northwestward, the system gradually intensified. Between November 9 and 10, reconnaissance missions into the depression found winds of 40 mph (65 km/h); however, the NHC did not upgrade it to a tropical storm, because weaken occurred shortly thereafter. Over the following few days, the system gradually turned southward and made landfall in the southwestern edge of the Yucatán Peninsula on November 12, shortly before dissipating. In late November, another tropical depression formed over the central Atlantic. A short-lived system, it formed on November 29 and dissipated on December 1.
This is a table of the storms in the 1975 Atlantic hurricane season. It mentions all of the season's storms and their names, landfall(s), peak intensities, damages, and death totals. Deaths in parentheses are additional and indirect(an example of such being a traffic accident or landslide), but are still related to that storm. The damage and death totals in this list include impacts when the storm was a precursor wave or post-tropical low, and all of the damage figures are in 1975 USD.
The following names were used for named storms (tropical storms and hurricanes) that formed in the North Atlantic in 1975. Storms were named Amy, Caroline, Doris, Eloise and Faye for the first time in 1975. The name Eloise was later retired. Names that were not assigned are marked in gray.