The 1940 Atlantic hurricane season officially began on June 16, 1940, and lasted until October 31, 1940. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin. Two flooding storms impacted the southern and eastern United States during August in relatively quick succession.
, the lowest associated with the storm. Around that time, maximum sustained winds reached 65 mph (100 km/h). Thereafter, the storm decelerated and began weakening. The storm curved eastward, before turning northeastward on May 25. By the following day, the storm weakened to a tropical depression. At 0600 UTC on May 27, the storm lost its identity while located south of Nova Scotia.
At the southern end of a weather front, a frontal wave developed into a tropical depression on August 3 just off the west coast of Florida, northwest of Tampa. The storm tracked generally westward, crossing the northern Gulf of Mexico while slowly strengthening. The hurricane made landfall near the Texas/Louisiana border on August 8 at peak intensity with winds of 100 mph (155 km/h). Once onshore, the storm turned due north and gradually weakened to a tropical depression before dissipating over northern Arkansas late on August 10. Prolific rainfall and flooding occurred over Acadiana due to this system, which is one of the wettest on record for the state of Louisiana. Six casualties and $6 million in damage from flooding can be attributed to this hurricane.
A tropical storm was first observed on August 5, north of the Lesser Antilles. It tracked generally to the northwest, and became a hurricane on August 9. Steady intensification took place as the storm approached the Southeastern United States. On August 11, the storm made landfall near the Georgia/South Carolina border as Category 2 hurricane with winds of 100 mph (155 km/h). Over the following three days, the system weakened to a tropical depression and executed a slow, re-curvature towards the east. The storm ultimately dissipated on August 14 over southern Virginia. Due to the hurricane's slow movement, it produced tremendous rainfall over a large area from South Carolina to Virginia. The hurricane caused around 100 deaths, 80 from the mountainous flooding, and $3 million in damage at the coastal area of Georgia and South Carolina. Damage estimates are not available from the extratropical remnant.
On August 26, a tropical depression developed well to the south of Bermuda. Tracking slowly west-northwestward, the depression maintained its intensity for nearly two days before attaining tropical storm status late on August 28. Faster intensification ensued thereafter, with the storm becoming a hurricane on August 29. At the same time, it began accelerating northwestwards towards North Carolina. After intensifying to a Category 2 hurricane on August 31, the system made an abrupt northeastward turn on September 1 and further accelerated its forward speed. Early the next day, the storm attained its peak intensity with winds of 105 mph (165 km/h) and a barometric pressure of 961 mbar (hPa; 28.38 inHg). After passing offshore of Cape Cod and approaching the Bay of Fundy, the storm weakened below hurricane strength and began losing its tropical characteristics. Shortly before striking New Brunswick early on September 3, the storm completed its transition into an extratropical cyclone. The system continued northeastward and dissipated later that day.
On September 7, a tropical depression form several hundred miles east of the Leeward Islands. Tracking west-northwestward, the depression maintained its intensity for over two days before becoming a tropical storm on September 10. Gradual strengthening followed thereafter, with the system attaining hurricane status north-northeast of Hispaniola on September 12. The hurricane continued to strengthen as it turned north-northeast. Upon reaching Category 2 strength, the storm did not strengthen further. Maintaining heading and intensity for the next two days, cooler water finally weakened the storm on September 15. However, Storm Five maintained hurricane intensity and struck southern Nova Scotia with 75 mph (121 km/h) winds. After traversing the western portion of the island, the system weakened below hurricane intensity and transitioned into an extratropical cyclone. The remnants of the storm turned eastward and gradually weakened. The system eventually dissipated on September 19 several hundred miles east of Newfoundland. No damage or human fatalities were reported.
A westward moving tropical depression formed east of Bluefields, Nicaragua on September 18. Early the next day, it intensified into a tropical storm as before making landfall in the country. Turning northwestward, the storm briefly weakened back to depression status before re-intensifying over the Gulf of Honduras on September 20. Early the next day, the storm made landfall on modern-day Belize before once again weakening to a tropical depression. Maintaining its northwestward movement, the system crossed the Yucatán Peninsula and emerged into the southern Gulf of Mexico early on September 22. For a third time, the system attained tropical storm status, with peak winds reaching 45 mph (75 km/h). As it neared the Texan coast, it slowed and turned to the east, paralleling the Texas and Louisiana coastlines before making landfall on September 24 over southern Louisiana. It dissipated the next day, after causing heavy flooding, amounting to 7 inches (180 mm) in some locations throughout its path.
On October 20, a tropical depression formed over the southwestern Caribbean Sea. Steadily intensifying, the system became a tropical storm later that day as it slowly moved westward. After turning more northwesterly, the system attained hurricane status, with peak winds ultimately reaching 80 mph (130 km/h). Maintaining that strength, the hurricane eventually turned west-southwestward as it neared the Nicaragua/Honduras border. Late on October 23, the hurricane made landfall in northern Nicaragua before quickly weakening onshore and dissipating later that day. Storm Eight caused considerable damage from freshwater flooding.
Another weak tropical storm (possibly subtropical) formed near the Turks and Caicos islands on October 24. The storm's winds peaked at 45 mph (75 km/h) as it rapidly accelerated northeastward. On October 26, the system transitioned into an extratropical cyclone east of Bermuda. After transitioning, the storm gradually slowed its forward speed and turned northward and intensified. The following day, the remnants acquired hurricane-force winds as the cyclone passed east of Newfoundland. During the afternoon of October 28, the storm weakened below hurricane-equivalent strength as it turned eastward. The system dissipated the following day well to the east of Newfoundland.