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The 1937 Atlantic hurricane season was a below-average hurricane season, featuring eleven tropical storms; of these, four became hurricanes. One hurricane reached major hurricane intensity, equivalent to a Category 3 or higher on the modern Saffir–Simpson scale. The United States Weather Bureau defined the season as officially lasting from June 16 to October 16. Tropical cyclones that did not approach populated areas or shipping lanes, especially if they were relatively weak and of short duration, may have remained undetected. Because technologies such as satellite monitoring were not available until the 1960s, historical data on tropical cyclones from this period are often not reliable. As a result of a reanalysis project which analyzed the season in 2012, a tropical storm and a hurricane were added to the Atlantic hurricane database (HURDAT). The official intensities and tracks of all storms were also revised by the reanalysis. The year's first storm formed on July 29 in the Gulf of Mexico, and the final system, a hurricane, dissipated over open ocean on October 21.
Most of the season's storms arose from the subtropics. Nova Scotia was a focus for storm activity with four storms reaching the Canadian province as extratropical cyclones. Two of these were the remnants of hurricanes; the first inflicted $1.5 million in damage on the apple crop in the Annapolis Valley, and the second tore up four breakwaters and sank or grounded several ships. The year's deadliest tropical cyclone was a tropical storm that struck Florida at the end of August. A squall associated with the storm caused the sinking of the SS Tarpon, killing 18 people. A short-lived tropical storm in October caused the wettest 48-hour period in the history of New Orleans, Louisiana, with of rainfall, causing the city's most destructive flood since the Great Mississippi Flood of 1927. A tropical storm striking parts of the U.S. Gulf Coast caused two deaths, but otherwise did minor damage. The season's strongest storm was estimated to have produced maximum sustained winds of and remained over the more central longitudes of the Atlantic.
The season's activity was reflected with an accumulated cyclone energy (ACE) rating of 66 units, below the 1931–1943 average of 91.2. ACE is a metric used to express the energy used by a tropical cyclone during its lifetime. Therefore, a storm with a longer duration will have high values of ACE. It is only calculated at six-hour increments in which specific tropical and subtropical systems are either at or above sustained wind speeds of , which is the threshold for tropical storm intensity. Thus, tropical depressions are not included here.
In Tampa, Florida, five-minute sustained winds reached , Clearwater, Florida documented of rainfall in a 24-hour period, the heaviest rains measured in connection with the passing tropical storm. Some roads were washed out in Clearwater and minor losses of fruit were documented in surrounding Pinellas County. Farther north, gusts at Hatteras, North Carolina peaked at . Telephone and power service was disrupted in Halifax, Nova Scotia as the storm's remnants produced 35-mph (55 km/h) winds in the city. Three boats moored there were destroyed.
Tropical Storm Two
On August 1, a weak trough was identified north of the Greater Antilles. It developed into a tropical depression by 18:00 UTC on August 2 while positioned just southwest of Long Island, Bahamas; further intensification into a tropical storm occurred over Current Island 24 hours later. The system curved around the western periphery of an area of high pressure, attaining peak winds of based on data from ships that intersected the cyclone. Unlike the previous cyclone, this tropical storm never transitioned into an extratropical cyclone, instead weakening to a tropical depression around 00:00 UTC on August 9 and dissipating east of Nova Scotia twelve hours later. Flooding rains from the system washed out roads and bridges in the state's northwestern counties. One squall associated with the tropical cyclone sank the SS Tarpon off Pensacola, drowning 18 of the 31 persons on board. Survivors remained at sea for up to 30 hours before being rescued. Rainfall totals of at least spread as far west as eastern Mississippi, with a maximum rainfall of observed in Vernon, Florida. Heavy rains in southeastern Alabama caused the Pea and Choctawhatchee rivers to flood, inflicting roughly $62,500 in damage to adjacent property and crops.
Hurricane Four
A strong tropical wave, originating near Cabo Verde around September 4, developed into a tropical storm by 00:00 UTC on September 9 while positioned about east-northeast of Barbuda. It intensified into the season's first hurricane within 24 hours, further maturing to Category 2 intensity with winds of by 06:00 UTC on September 12. The small hurricane moved steadily northwest throughout its lifespan, passing east of Bermuda before weakening to a tropical storm late the next day. It acquired well-defined frontal boundaries by 06:00 UTC on September 14, marking the system's transition into an extratropical cyclone. It made landfall in Nova Scotia and either elongated into a trough or merged with a frontal system over far eastern Canada twelve hours later.
Tropical Storm Five
As part of the Atlantic hurricane reanalysis project, a previously unidentified tropical cyclone was discovered in 2012. Similar to the evolution of the season's first tropical cyclone, an area of low pressure formed along a dissipating frontal boundary early on September 10. It developed into a tropical storm by 06:00 UTC that day while located roughly south-southwest of Bermuda. The storm moved northwest over the next day, making a close approach to the Northeastern United States before veering to the northeast. It reached peak winds of around 18:00 UTC on September 11, when the structure of the system more resembled a subtropical cyclone than a strictly tropical one. It transitioned into an extratropical cyclone six hours later, striking Nova Scotia before becoming absorbed into the larger circulation of a non-tropical entity around 06:00 UTC on September 12. Two people drowned after their canoe capsized in rough seas generated by the storm near Everglades City.
Hurricane Eight
A tropical wave likely emerged from the western coast of Africa around September 14. It developed into a tropical cyclone at some point of the next few days, with a specific date unclear in the absence of surface observations. At 06:00 UTC on September 20, a hurricane was conclusively identified about halfway between Cabo Verde and the Leeward Islands. It gained strength on a general northwest heading, intensifying into a Category 2 hurricane and attaining peak winds of from September 24–25. Slight weakening occurred as the system passed well north of Bermuda. It transitioned into an extratropical cyclone by 06:00 UTC on September 26 and struck Nova Scotia before turning northeast across Newfoundland and into the northern Atlantic. The extratropical cyclone was last noted over Iceland at 12:00 UTC on September 28, after which time it likely merged with another non-tropical low.
Tropical Storm Nine
At 06:00 UTC on September 26, a tropical depression formed just north of Cuba. It intensified into a tropical storm by 18:00 UTC the following day based on reports from two ships. After attaining peak winds of , the cyclone quickly transitioned to an extratropical cyclone by 12:00 UTC on September 28 as multiple fronts became intertwined with the circulation. The extratropical cyclone continued to parallel the U.S. East Coast, eventually making landfall in Newfoundland early on September 30. It strengthened into a hurricane-force low on October 1 but ultimately dissipated two days later as it merged with another cyclone and became increasingly elongated. City streets were submerged under as much as of water. Blue laws were suspended for half a day to allow grocery store food supplies to reach stranded areas. Crops around the city sustained considerable damage. At Belle Chasse, Louisiana, the of rain recorded in 24 hours set the state record for the highest 24-hour rainfall in October. Heavy rains extended into counties in southern Mississippi and southern Arkansas.
Hurricane Eleven
Similar to Tropical Storm Five, a new tropical cyclone that was not recognized in real time was found to have existed over the northern Atlantic. From October 16–17, a cold front moved eastward across the basin. An area of low pressure formed along the southern end of the dissipating boundary, initially harboring characteristics of an extratropical cyclone. This low became more symmetric while also intensifying, transitioning into a hurricane by 00:00 UTC on October 19 while located roughly southeast of Newfoundland. The system attained peak winds of within six hours and weakened shortly thereafter while moving west-northwest. It fell to tropical storm intensity by early on October 20; by 00:00 UTC the next day, there were no further indications of the storm. It either dissipated or was absorbed by a front encroaching from the west.