Hurricane One

A small 90 mph (150 km/h) hurricane was first observed on June 25, about 75 mi (120 km) southeast of Freeport, Texas. It tracked westward, moving ashore near Matagorda Bay later that night near peak intensity, with an estimated minimum barometric central pressure of 977 mbar (28.9 inHg); due to lack of observations, it is possible the hurricane struck as the equivalent of a Category 2 hurricane on the Saffir–Simpson scale. The cyclone slowly weakened as it turned northwestward, with hurricane-force wind gusts reported 24 hours after landfall in current-day Medina County. It is estimated that the storm dissipated early on June 28 over central Texas.^[3]

The hurricane produced heavy damage near where it moved ashore, having been described as the most disastrous experienced there to date. The winds destroyed every wharf and several houses in Port Lavaca. On Matagorda Island, the saltwater contaminated the fresh water supply, and in Matagorda Bay, heavy shipping losses were reported. As the cyclone progressed inland, it dropped light to moderate rainfall, peaking at around 3 in (76 mm) in Corpus Christi. A fort near current day Laredo reported 2.48 in (63 mm) of precipitation. Across its path, the winds downed several trees and houses, leaving two people injured and contributing to a death when a sick person was exposed to the storm.^[3]

Hurricane Two

A moderate hurricane made landfall near Tampico, which was described as having moved ashore before July 7; the Hurricane Research Division assessed the date as July 5. Heavy damage was reported in Tampico.^[3]

Tropical Storm Three

A tropical storm passed through the southern Lesser Antilles on July 10. Overall documentation on the storm was weak, and its track elsewhere is unknown.^[3] Owing to the lack of information, climate researcher Michael Chenoweth proposed the removal of this storm from HURDAT in a 2014 reanalysis study.^[5]

Hurricane Four

Great Florida Middle Panhandle Hurricane of August 1851 or Hurricane San Agapito of 1851^[6] was first observed on August 16 about 775 mi (1,245 km) east of Barbados. It tracked west-northwestward, attaining hurricane status on August 17 as it approached the Lesser Antilles. Shortly thereafter, the hurricane passed between Antigua and Saint Kitts and later south of Saint Croix.^[3] On August 18 it brushed the southern coast of Puerto Rico, though it affected the entire island due to a large size of the storm.^[6] The next day it made landfall on the southern coast of the Dominican Republic. The cyclone rapidly weakened to tropical storm status over Hispaniola, though it regained hurricane status as it paralleled the southern coast of Cuba just offshore. Late on August 20, the cyclone crossed western Cuba, briefly weakening to tropical storm status before again regaining hurricane status in the southeastern Gulf of Mexico. It quickly strengthened and reached peak winds of 115 mph (185 km/h) early on August 23 about 215 mi (345 km) south-southeast of Pensacola, Florida. Turning northeastward, the hurricane moved ashore near Panama City, Florida at peak intensity,^[3] with an estimated barometric pressure of 960 mbar (28 inHg).^[7] It accelerated across the Southeastern United States, weakening to a tropical storm before exiting North Carolina into the Atlantic Ocean on August 25. On August 27, it was last observed over Newfoundland as a weak tropical storm.^[3]

The hurricane passed near Saint Lucia on August 17,^[3] where high tides and rough seas were reported.^[8] Flooding was reported in northern Puerto Rico during its passage.^[6] Impact is unknown in Hispaniola and Cuba.^[3] The hurricane produced an estimated storm tide of 12 ft (3.7 m) at St. Marks;^[3] the combination of waves and the storm tide flooded coastal areas, destroying 50% of the cotton crops in some areas.^[4] Rough seas destroyed a brig, killing 17 people, and another person drowned due to a shipwreck. Many ships were expected to have been lost in the storm, resulting in fear of potentially hundreds of deaths. The storm caused heavy damage along the coastline, and in Apalachicola the winds destroyed the roofs of all but two or three buildings. Dog Island Light was destroyed, resulting in five deaths. Further inland, many houses were blown over in Tallahassee, totaling $60,000 in damage (1851 USD). Heavy damage was reported in Alabama, including destroyed crops and damaged houses; damage in the state was less than in Florida.^[4] Hurricane-force winds extended into southwestern Georgia,^[3] while tropical storm force winds were reported along the coastline. In Savannah, the winds damaged many houses and downed many trees.^[9] In North Carolina and Virginia, winds from the storm destroyed crop fields and small buildings; in the region, it was described as the worst storm in 30 years.^[10] Storm damage was reported as far north as Cambridge, Massachusetts.^[8]

Tropical Storm Five

On September 13, a tropical storm was first observed about 225 mi (360 km) southeast of Cape Hatteras, North Carolina.^[3] A nearby ship with the call sign Cushnoc reported estimated winds of 60 mph (95 km/h), which was judged to be the peak intensity of the tropical storm. Another ship on September 16 reported similar winds in the same location;^[11] Thus, it was estimated to have remained nearly stationary for three days. Its complete track is unknown.^[3]

Tropical Storm Six

A tropical storm developed on October 16 about 155 mi (250 km) east of Cape Canaveral, Florida. It tracked northeastward, gradually strengthening to attain peak winds of 70 mph (110 km/h) early on October 17. On October 18, the storm turned more to the north-northeast as its forward motion increased. Gradually weakening, the storm dissipated late on October 19 after making landfall in Rhode Island.^[3] Chenoweth proposed the removal of this system from HURDAT, arguing that reports only supported the presence of a strong high-pressure system, rather than a tropical cyclone.^[5]

Other systems

• On August 2, a hurricane was reported in the vicinity of Tampico.^[12] However, it was not listed as a tropical cyclone in the official hurricane database.^[1]
• An assessment by scholar Michael Chenoweth indicated the presence of a hurricane in the vicinity of western Jamaica around November 7. It is not currently listed in the official hurricane database.^[5]