The 1780 Atlantic hurricane season ran through the summer and fall in 1780. The 1780 season was extraordinarily destructive, and was the deadliest Atlantic hurricane season in recorded history with over 28,000 deaths. Four different hurricanes, one in June and three in October, caused at least 1,000 deaths each; this event has never been repeated and only in the 1893 and 2005 seasons were there two such hurricanes. The season also had the deadliest Atlantic hurricane of all time, since known as the Great Hurricane of 1780.
Landfalling storms affected the Lesser Antilles, Puerto Rico, the Dominican Republic, Jamaica, Cuba, Bermuda, Louisiana, Georgia, Florida, and the New England states.
This destructive season should be seen against a backdrop of the American Revolution, which involved hostilities in the Caribbean by the fleets of Spain, France and the Dutch Republic operating against British fleets with the concomitant greater risk of loss of life due to increased exposure of warships and transports to hazardous weather conditions. This critical coincidence is at least partially responsible for the unprecedented losses of life inflicted, especially in the three fierce hurricanes that struck in quick succession during October.
The San Antonio Hurricane, also known as the St. Lucia Hurricane. On June 13, a hurricane "caused deaths and losses" on Puerto Rico, after having also struck St. Lucia, where it killed around 4,000 to 5,000. It later went on to the Dominican Republic.
New Orleans experienced a powerful hurricane on August 24, with winds gusting over 160 mph completely destroying 39 of the 43 buildings in Grand Isle, Louisiana then the eye passing over New Orleans that night, severely damaging structures in what is now known as the French Quarter, causing harvest-ruining crop damage, severe flooding, and tornadoes. This was from an entry from Count de Lafrenière's diary. It killed around 25 people.
On August 25, St. Kitts in the Leeward Islands was struck by a storm.
A strong storm formed in the southern Caribbean Sea on October 1. Early on, it sunk the British transport ship Monarch, killing several hundred Spanish prisoners and the ship's entire crew. The hurricane began to move northwest towards Jamaica, where it destroyed the port of Savanna-la-Mar on October 3. Many of the town's residents gathered at the coast to spectate, and 20 foot surge engulfed the onlookers, docked ships, and many of the town's buildings. In the nearby port village of Lucea, 400 people and all but two structures perished, with 360 people also killed in the nearby town of Montego Bay. It would go on to sink the British frigate Phoenix (killing 200 of it crew) and ships-of-the-line Victor, Barbadoes, and Scarborough and crippled many others. It continued its direction, and hit Cuba on October 4, followed by a pass over the Bahamas. By some estimates, the storm caused 3,000 deaths.
The second hurricane of October 1780 is still referred to as "The Great Hurricane" in some places. Its official name, and how it is referred to by most Antillians is "San Calixto Hurricane" and it is also called the "Great Hurricane of the Antilles". The storm had winds of 135 miles per hour or greater and forward motion speed of less than 10 miles per hour. Causing a record 22,000 deaths in the eastern Caribbean Sea, it rates as the all-time deadliest hurricane in the Atlantic. "Further, the historical importance of the storm was heightened by the presence of the powerful fleets of Britain and France, both maneuvering on nearby islands to strike blows at each other's rich possessions in the Antilles."
The storm formed before or on October 10. It devastated the island of Barbados on October 10 with 200+ mph wind gusts, killing 4,300 and creating an economic depression. St. Vincent suffered a 20-foot (6 meter) storm surge. The storm went on to kill 6,000 people on the island of St. Lucia and 9,000 on Martinique, with its capital city, St. Pierre, becoming almost completely demolished. It later moved northwestward toward the island of St. Eustatius, killing 4,000 to 5,000 and devastating Puerto Rico, Dominique, and Bermuda. The storm dissipated on or after October 18.
A powerful hurricane in the Eastern Gulf of Mexico struck a Spanish war fleet of 64 vessels under José Solano en route from Havana, Cuba to attack Pensacola, Florida, then the capital of British West Florida. The ships had 4,000 men aboard under the military command of Bernardo de Gálvez, and 2,000 died. The slow-moving hurricane, known to history as "Solano's hurricane", was first noted near Jamaica on October 15. Progressing northwestwards it likely crossed the western end of Cuba, before shifting northeastwards to Apalachee Bay. It struck Solano's fleet on October 20. According to Emanuel (2005), it dissipated somewhere over the southeastern United States around October 22, but Chenoweth (2006) argues that it crossed the U.S. and finally dissipated over the North Atlantic on October 26. It has likely been detected in tree-ring isotope records from Valdosta, Georgia.
In late October, a tropical cyclone struck Barbados and then St. Lucia on October 23.
Around November 17, a tropical cyclone moved up the east coast of the United States disrupting the British blockade of the New England states. It is unknown whether this storm was fully tropical.