The storm was first analyzed by ship data south of the Cape Verde Islands on September 9. Over the next ten days, it steadily gathered strength and slowly tracked to the west-northwest. By September 20, while centered east of the Bahamas, the hurricane is estimated to have reached Category 5 intensity. In response to a deep trough over Appalachia, the hurricane veered northward, sparing the Bahamas, Florida, the Carolinas, and the Mid-Atlantic. At the same time, a high pressure system was centered north of Bermuda, preventing the hurricane from making an eastward turn out to sea. Thus, the hurricane was effectively squeezed to the north between the two weather systems.
Late on September 20, this set-up caused the storm's forward speed to increase substantially, ultimately reaching 70 mph, the highest forward velocity ever recorded in the annals of hurricanes. This extreme forward motion, being in the same general direction as the winds on the eastern side of the storm as it proceeded north, caused the perceived wind speed in areas east of the eye to be far higher than would be the case with a hurricane of more typical forward speed. (Winds rotate counter-clockwise around all low pressure systems in the Northern Hemisphere, thus winds on the right side of a hurricane, "right" being relative to the direction of motion of the storm itself, are moving in the same general direction as the hurricane. Therefore, the forward motion increases the observed wind speed for points to the right of the eye of the hurricane and decreases the observed wind speed for points to the left of the eye, but in a complex way that defies crude addition or subtraction of the forward motion from the "intrinsic" wind speed of the hurricane.) During the early hours of September 21, the storm, centered several hundred miles to the southeast of Cape Hatteras, weakened slightly. By 8:30 am EDT, the hurricane was centered approximately 100 miles (160 km) due east of Cape Hatteras, and its forward speed had increased to well over 50 mph. This rapid movement did not give the hurricane a sufficient amount of time to weaken over the cooler waters before it reached Long Island. During the 9:00 am EDT hour, the hurricane sped through the Virginia tidewater. Between 12:00 pm and 2:00 pm EDT, the New Jersey coastline and New York City caught the western edge of the hurricane. At the same time, weather conditions began to deteriorate rapidly on Long Island as well as along the southern New England coast. The hurricane made landfall at Bellport on Long Island's Suffolk County sometime between 2:10 pm and 2:40 pm EDT as a category 3 hurricane with sustained winds of 120 mph. The storm made a second landfall still as a category 3 hurricane somewhere between Bridgeport and New Haven, Connecticut, around 4:00 pm with sustained winds of 115 mph.
By 5:00 pm EDT, the eye moved into western Massachusetts, and by 6:00 pm EDT, the hurricane reached Vermont. Both Westfield, Massachusetts, and Dorset, Vermont, reported calm conditions and partial clearing during passage of the eye, which is a rather unusual occurrence for a New England hurricane. As the hurricane continued into northern Vermont, it began to lose tropical characteristics. Still carrying hurricane-force winds, the storm crossed into Quebec at approximately 10:00 pm EDT, while transitioning into a post-tropical low. The post-tropical remnants dissipated over northern Ontario a few days later.
In 1938 United States forecasting lagged behind forecasting in Europe, where new techniques of analyzing air masses and taking into account the influence of fronts were being used. A confidential report by the United States Forest Service, the parent agency of the United States Weather Bureau, had described the forecasting of the bureau as "a sorry state of affairs" where forecasters had poor training and systematic planning was not used and where forecasters had to "scrape by" to get information wherever they could. On September 19 the Jacksonville, Florida, office of the United States Weather Bureau issued a warning that a hurricane might hit Florida. Residents and authorities who had endured the Labor Day Hurricane 3 years prior made extensive preparations. When the storm turned north the office issued warnings for the Carolina coast and transferred authority to the bureau's headquarters in Washington. At 9:00 am on September 21 the Washington office issued northeast storm warnings north of Atlantic City and south of Block Island and southeast storm warnings from Block Island to Eastport, Maine. The advisory underestimated the storm's intensity and said the storm was farther south than it actually was. The office had yet to forward any information about the hurricane to the New York City office. At 10:00 am the bureau downgraded the hurricane to a tropical storm. The 11:30 am advisory mentioned gale-force winds but nothing about a tropical storm or hurricane. That day 28-year-old rookie Charles Pierce was standing in for two veteran meteorologists. Pierce concluded the storm would be squeezed by a high-pressure area located to the west of the hurricane and a high-pressure area located to the east of the hurricane and be forced to ride up a trough of low pressure into New England. A noon meeting was called and Pierce presented his conclusion but was overruled by "celebrated" chief forecaster Charles Mitchell and his senior staff. In Boston meteorologist E.B. Rideout told his WEEI radio listeners, to the skepticism of his peers, that the hurricane would hit New England. At 2:00 pm, as hurricane-force gusts were occurring on Long Island's South Shore and near hurricane-force gusts on the coast of Connecticut, the Washington office issued an advisory saying the storm was 75 miles east-southeast of Atlantic City and would pass over Long Island and Connecticut. Reanalysis of the storm suggests the hurricane was farther north (just 50 miles from Fire Island), stronger, and larger than the advisory said.
The majority of the storm damage was from storm surge and wind. Damage was estimated at $308 million, (the equivalent of $5.1 billion adjusted for inflation in 2016 dollars), making it among the most costly hurricanes to strike the U.S. mainland. It is estimated that if an identical hurricane struck in 2005 it would have caused $39.2 billion (2005 dollars) in damage, due to changes in population and infrastructure.
Approximately 600 people died in the storm in New England, most in Rhode Island, and up to 100 people elsewhere in the path of the storm. An additional 708 people were reported injured.
In total, 4,500 cottages, farms, and other homes were reported destroyed. An additional 25,000 homes were damaged. Other damages included 26,000 automobiles destroyed and 20,000 electrical poles toppled. The hurricane also devastated the forests of the Northeast, knocking down an estimated 2 billion trees in New York and New England. Freshwater flooding was minimal, however, as the quick passage of the storm decreased local rainfall totals, with only a few small areas receiving over 10 inches (250 mm).
Over 35% of New England's total forest area was affected. In all, over 2.7 billion board feet of trees fell because of the storm. 1.6 billion board feet of the trees were salvaged. The Northeastern Timber Salvage Administration (NETSA) was established to deal with the extreme fire hazard that the fallen timber had created. In many locations, roads from the fallen tree removal were visible decades later and in some cases, became trails still used today. The New York, New Haven and Hartford Railroad from New Haven to Providence was particularly hard hit, as countless bridges along the Shore Line were destroyed or flooded, severing rail connections to badly affected cities (such as Westerly, Rhode Island) in the process. More than 50 people perished on Long Island in the storm's wake. All the shore lines were very vulnerable to the high winds and flooding waves, and anyone who was along or near the shores was directly in harm's way. Due to the lack of technology back in 1938, Long Island residents were not warned of the hurricane's arrival, leaving little to no time to prepare or evacuate. Long Island was struck first, before New England, Vermont, New Hampshire, and Quebec, earning the storm the nickname the "Long Island Express." The winds reached up to 150 mph with waves surging to around 25–35 feet high. Ten new inlets were created on eastern Long Island. The surge rearranged the sand at the Cedar Point Lighthouse so that the island became connected to what is now Cedar Point County Park. The surging water created the present-day Shinnecock Inlet by carving out a large section of barrier island separating Shinnecock Bay from the Atlantic. The storm toppled the landmark steeple of the tallest building in Sag Harbor, the Old Whaler's Church. The steeple has not been rebuilt. Wading River suffered substantial damage. In Greenport, on the North Fork of Long Island, the storm blew down the movie theater located on Front Street. The fishing industry was destroyed, as was half of the apple crop.
The hurricane also played an interesting role in the centuries-old Yale-Harvard rivalry. At the time, both schools had 2,000+ acre forests managed by their forestry departments. These forests were wiped out by the hurricane, thus rendering them useless for having a timber management program. However, Yale had a backup forest at Great Mountain in northwestern Connecticut, which was spared from the totality of the damages. Hence, they were able to keep their forestry program running, which maintains operation today. Meanwhile, Harvard's program was reduced to a small program and no longer a major player in the forestry game.
The western side of the hurricane caused sustained tropical storm-force winds, high waves, and storm surge along much of the New Jersey coast. In Atlantic City, the surge destroyed much of the boardwalk, and the bridge between Atlantic City and Brigantine collapsed, stranding at least 2,000. Additionally, the surge inundated several coastal communities; Wildwood was under 3 feet (0.91 m) of water at the height of the storm, and in Bay Head, the boardwalk was destroyed and dozens of cottages washed into the ocean. Crops sustained wind damage. The maximum recorded wind gust was 70 mph at Sandy Hook.
The area escaped the worst of the wind and storm surge because it was hit by the storm's weaker western side. Winds were recorded at 60 mph at Central Park, Battery Park recorded sustained winds of 70 mph with gusts to 80 mph, and a gust of 90 mph was recorded 500 feet above ground at the Daily News Building. Winds were estimated at 120 mph on top of the Empire State Building. The highest winds were from the north to northwest on the back side of the storm. The storm surge was 8½ feet at the Battery and the Mean Low Water storm tide was 16¾ feet at Willets Point. In New York Harbor, the waters rose 7 feet in a half-hour.
In New York City and Long Island, schools were dismissed early. Extensive street flooding occurred because debris blocked drains. The East River flowed three blocks and flooded a Consolidated Edison (Con Ed) plant at 133rd Street, causing power to fail in Manhattan north of 59th Street and in the Bronx for several minutes to a few hours. Railroad and ferry services were suspended for a time. The Staten Island Ferry boat Knickerbocker with 200 passengers aboard got stuck in the terminal. Bridges and tunnels connecting Manhattan to the outside were closed until the following afternoon. 95% of Nassau County lost power, where floods brought traffic to a halt. In Manhasset Bay, almost 400 boats were ripped from their moorings and smashed or sunk, with more than 100 washing up on the beach by the Port Washington Yacht Club. Similar scenes occurred in other locations on the north shore. The J.P. Morgan estate in Glen Cove was heavily damaged. The wife of New York City mayor Fiorello La Guardia was forced to wait out the storm on the second floor of their Northport cottage. Mitchel Field army airfield, which was buffeted by winds of nearly 100 mph, was under water that was over knee-deep. In Williston Park, residents of 50 homes needed to be rescued by rowboat when heavy rain the previous few days combined with the rain from the hurricane to overflow a pond.
Eastern Long Island experienced the worst of the storm. The Dune Road area of Westhampton Beach was obliterated, resulting in 29 deaths. A cinema in Westhampton was also swept out to sea; about 20 people at a matinee and the theater projectionist landed two miles (3 km) into the Atlantic and drowned. There were 21 other deaths through the rest of the East End of Long Island. The storm surge temporarily turned Montauk into an island as it flooded across the South Fork at Napeague and obliterated the tracks of the Long Island Rail Road.
Being exposed to the storm due to its shorelines, Long Island was hit hard. The estimated storm tide was 15 feet in this region. A mean low water storm tide of 8 feet was recorded at Port Jefferson. About 50 people perished in the storm's wake. All the shore lines were very vulnerable to the high winds and flooding waves, and anyone who was along or near the shores was directly in harm's way.
Ten new inlets were created on eastern Long Island. The surge rearranged the sand at the Cedar Point Lighthouse so that the island became connected to what is now Cedar Point County Park. The surging water created the present-day Shinnecock Inlet by carving out a large section of barrier island separating Shinnecock Bay from the Atlantic. The storm toppled the landmark steeple of the tallest building in Sag Harbor, the Old Whaler's Church. The steeple has not been rebuilt. Wading River suffered substantial damage.
In Greenport, on the North Fork of Long Island, the storm blew down the movie theater located on Front Street.
The fishing industry was destroyed, as was half of the apple crop.
The storm surge hit Westerly, Rhode Island, at 3:50 pm EDT, resulting in 100 deaths.
The tide was even higher than usual because of the autumnal equinox and full moon. The hurricane produced storm tides of 14 to 18 feet (5 m) across most of the Long Island and Connecticut coast, with 18 to 25-foot (8 m) tides from New London east to Cape Cod. The storm surge was especially violent along the Rhode Island shore, sweeping hundreds of summer cottages out to sea. Low-lying Block Island offshore was almost completely underwater, and many drowned. As the surge drove northward through Narragansett Bay, it was restricted by the Bay's funnel shape and rose to 15.8 feet above normal spring tides, resulting in more than 13 feet (4.0 m) of water in some areas of downtown Providence. Several motorists were drowned in their automobiles. In Jamestown, seven children were killed when their school bus was blown into Mackerel Cove. Due in part to the economic difficulties of the Great Depression, many stores in downtown Providence were looted by mobs, often before the flood waters had fully subsided.
Many homes and structures along the coast were destroyed, as well as many structures inland along the hurricane's path. Entire beach communities on the coast of Rhode Island were obliterated. Napatree Point, a small cape that housed nearly 40 families between the Atlantic Ocean and Little Narragansett Bay just off of Watch Hill, Rhode Island, was completely swept away. Today, Napatree is a wildlife refuge with no human inhabitants. One house in Charlestown, Rhode Island, was lifted and deposited across the street, where it stood, inhabited, until it was demolished in August 2011. Even to this day, concrete staircases and boardwalk bases destroyed by the hurricane can be found when sand levels on some beaches are low. The boardwalk along Easton's Beach in Newport was completely destroyed by the storm.
A few miles from Conanicut Island, Whale Rock Light was swept off its base and into the raging waves, killing keeper Walter Eberle. His body was never found.
At Prudence Island, the Prudence Island Light suffered a direct blow from the storm surge, which measured 17'5" at Sandy Point. The masonry tower was slightly damaged. However, the adjoining lightkeeper's home was utterly destroyed and washed out to sea, killing the lightkeeper's wife and son, as well as the former lightkeeper and a couple who left their summer cottages near the lighthouse and sought shelter in the (perceived) sturdier lightkeeper's home. The lightkeeper, George T. Gustavus, was thrown free from the wreckage of the house and was saved by an island resident who held a branch into the water from the cliffs further down the coast. Gustavus and Milton Chase, the owner of the island's power plant, reactivated the light during the storm by running a cable from the plant to the light and installing a light bulb, marking the first time the light was lit with electricity.
Because of the massive flooding from the 1938 storm, and from the even higher 14.4 foot (4.4 meters) storm surge that resulted from 1954's Hurricane Carol, in 1966 the Fox Point Hurricane Barrier was completed to avoid such extreme storm surges from ever again flooding downtown Providence.
The original parchment of the 1764 Charter of Brown University was washed clean of its text when its vault in a Providence bank was flooded.
Newport recorded the highest water level of the storm, at 3.53 meters above mean sea level according to a NOAA study. This storm level is 0.98 meters above the SLOSH model of a 100-year storm, and one estimate is that this water level "reflects a storm occurring roughly once every 400 years." A study of sand deposits also gives evidence that this was the strongest hurricane to hit Rhode Island in over 300 years.
Eastern Connecticut was on the eastern side of the hurricane. Long Island acted as a buffer against large ocean surges, but the waters of Long Island Sound rose to unimaginable heights. Small shoreline towns to the east of New Haven had nearly complete destruction from the water and winds. To this day, the 1938 hurricane holds the record for the worst natural disaster in Connecticut's 350-year history.
The mean low-water storm tide was 14.1 feet at Stamford, 12.8 feet at Bridgeport, and 10.58 feet at New London, which remains a record high.
In the beach towns of Madison, Clinton, Westbrook, and Old Saybrook, buildings were found as wreckage across coastal roads. Actress Katharine Hepburn waded to safety from her Old Saybrook beach home, narrowly escaping death. She stated in her 1991 book that 95% of her personal belongings were either lost or destroyed, including her 1932 Oscar, which was later found intact. In Old Lyme, beach cottages were flattened or swept away. At Stonington, the Bostonian, a NYNH&H passenger train, became stuck in debris. Two passengers died when they drowned while attempting to escape, before the crew was able to clear the debris and get the train moving. Along the Stonington shorefront, buildings were swept off their foundations and found two miles (3 km) inland. Rescuers later searching for survivors in the homes in Mystic found live fish and crabs in kitchen drawers and cabinets.
New London was first swept by the winds and storm surge, after which the waterfront business district caught fire and burned out of control for 10 hours. Stately homes along Ocean Beach were leveled by the storm surge. The permanently anchored 240-ton lightship at the head of New London Harbor was found on a sand bar two miles (3 km) away.
Interior sections of the state experienced widespread flooding as the hurricane's torrential rains fell on soil already saturated from previous storms. The Connecticut River was forced out of its banks, inundating cities and towns from Hartford to Middletown.
African-American novelist Ann Petry drew on her personal experiences of the hurricane in Old Saybrook in her 1947 novel, Country Place. Although the novel is set in the immediate aftermath of World War II, Petry identified the 1938 storm as the source for the storm that is at the center of her narrative.
The eye of the storm followed the Connecticut River north into Massachusetts, where the winds and flooding killed 99 people. In Springfield, the river rose six to 10 feet (3 m) above flood stage, causing significant damage. Up to six inches (152 mm) of rain fell across western Massachusetts, which, combined with over four inches (102 mm) that had fallen a few days earlier, produced widespread flooding. In Chicopee, flash flooding on the Chicopee River washed away the Chicopee Falls Bridge, while the Connecticut River flooded most of the Willimansett section. Residents of Ware were stranded for days and relied on air-dropped food and medicine. After the flood receded, the town's Main Street was a chasm in which sewer pipes could be seen.
To the east, the surge left Falmouth and New Bedford under eight feet of water. Two-thirds of all the boats in New Bedford harbor sank. Several homes washed away on Atlantic Boulevard in Fall River, whose foundations can still be found on the beach today. The Blue Hill Observatory registered sustained winds of 121 mph (195 km/h) and a peak gust of 186 mph (299 km/h), which is the strongest hurricane-related surface wind gust ever recorded in the United States. A 50-foot wave, the tallest of the storm, was recorded at Gloucester.
The storm entered Vermont as a Category 1 hurricane at approximately 6:00 pm EDT, reaching northern Vermont, Burlington, and Lake Champlain around 8:00 pm. Hurricane-force winds caused extensive damage to trees, buildings, and power lines. Over 2,000 miles (3,200 km) of public roads were blocked, and it took months for crews to reopen some of the roads. In Montpelier, 120 miles (190 km) from the nearest coast, salt spray was seen on windows. A train was derailed in Castleton. The storm killed five people in Vermont. Maple and sugar groves were damaged. The 1938 hurricane has been the only tropical cyclone to make a direct hit on Vermont in its recorded history; it remains the only one known to have struck Vermont as a hurricane.
Even though the storm center tracked further west, through Vermont, New Hampshire, received appreciable damage. As in Vermont, very high winds brought down numerous trees and electric lines, but rainfall totals in New Hampshire were significantly less than those in other states. Only 1 inch (25 mm) of rain fell in Concord. Damage at Peterborough was worse, however; total damage there was stated to be $500,000 (1938 dollars, $6.5 million 2005 dollars), which included the destruction of 10 bridges. Much of the lower downtown burned because floodwaters prevented firefighters from reaching and extinguishing the blaze. Other communities also suffered considerable damage to forest resources. In New Hampshire, 13 people perished. At Mt. Washington, winds gusted to 163 miles per hour (262 km/h) and knocked down part of a trestle on the Cog Railway.
In Maine, buildings and trees were damaged and power outages occurred. Storm surge was minimal, and winds remained below hurricane strength. The storm did not claim any lives in Maine.
The western periphery of the hurricane brought heavy rain and gusty winds to Delaware and southeastern Maryland. Damage, if any, is believed to have been minimal.
As the hurricane was transitioning into an extratropical cyclone, it tracked into southern Quebec. By the time the system initially crossed into Canada, it continued to produce heavy rain and very strong winds, but interaction with land had taken its toll. Nevertheless, the hurricane managed to blow down numerous trees throughout the region. Otherwise, damage was generally minimal.