The Okeechobee hurricane of 1928, also known as the San Felipe Segundo hurricane and Florida's Forgotten Storm, was one of the deadliest hurricanes in the recorded history of the North Atlantic basin, and the fourth deadliest hurricane in the United States, only behind the 1900 Galveston hurricane, 1899 San Ciriaco hurricane, and Hurricane Maria. The hurricane killed an estimated 2,500 people in the United States; most of the fatalities occurred in the state of Florida, particularly in Lake Okeechobee. It was the fourth tropical cyclone, third hurricane, and only major hurricane of the 1928 Atlantic hurricane season, and remains the deadliest disaster in Florida's history to date. It developed off the west coast of Africa on September 6 as a tropical depression, but it strengthened into a tropical storm later that day, shortly before passing south of the Cape Verde islands. Further intensification was slow and halted late on September 7. About 48 hours later, the storm strengthened and became a Category 1 hurricane on the Saffir–Simpson hurricane wind scale. Still moving westward, the system reached Category 4 intensity before striking Guadeloupe on September 12, where it brought great destruction and resulted in 1,200 deaths. The islands of Martinique, Montserrat, and Nevis also reported damage and fatalities, but not nearly as severe as in Guadeloupe.

Around midday on September 13, the storm strengthened into a Category 5 hurricane and peaked with sustained winds of 160 mph (260 km/h). About six hours later, the system made landfall in Puerto Rico; it remains the only tropical cyclone on record to strike the island at Category 5 intensity. Very strong winds resulted in severe damage in Puerto Rico; 24,728 homes were destroyed and 192,444 were damaged throughout the island, leaving over 500,000 people homeless. Heavy rainfall also led to extreme damage to vegetation and agriculture. On Puerto Rico alone, there were 312 deaths and about US$50 million ($916 million today) in damage. While crossing the island and emerging into the Atlantic, the storm weakened slightly, falling to Category 4 intensity. It began crossing through the Bahamas on September 16, where it resulted in 18 fatalities.

The storm made landfall near West Palm Beach, Florida, early on September 17, with winds of 145 mph (233 km/h). In the city, more than 1,711 homes were destroyed; the effects were most severe around Lake Okeechobee. The storm surge caused water to pour out of the southern edge of the lake, flooding hundreds of square miles to depths as great as 20 feet (6.1 m). Numerous houses and buildings were swept away in the cities of Belle Glade, Canal Point, Chosen, Pahokee, and South Bay, Florida. At least 2,500 people drowned, while damage was estimated at $25 million ($458 million today). The system weakened significantly while crossing Florida, falling to Category 1 intensity late on September 17. It curved north-northeast and briefly emerged into the Atlantic on September 18, but soon made another landfall near Edisto Island, South Carolina, with winds of 85 mph (137 km/h). Early on the following day, the system weakened to a tropical storm and became an extratropical cyclone over North Carolina hours later. Overall, the hurricane caused $100 million in damage ($1831 million today) and killed at least 4,114 people.

On September 6, ships reported a tropical depression developing just off the west coast of Africa near Dakar, Senegal. On the next day, a ship reported winds of 60 mph (97 km/h), or tropical storm status; on this basis, the Atlantic hurricane reanalysis project estimated that the system attained tropical storm status late on September 6. However, lack of observations for several days prevented the system from being classified in real time as it moved generally westward across the Atlantic Ocean. On September 10, the S.S. Commack first observed the storm about 900 mi (1,450 km) to the east of Guadeloupe, which at the time was the most easterly report of a tropical cyclone ever received through ship's radio. Later that day, two other ships confirmed the intensity of the storm, and the Hurricane Research Division estimated it strengthened into a hurricane at 18:00 UTC on September 10.

As the storm neared the Lesser Antilles, it continued to intensify. Between 17:30 and 18:30 UTC on September 12, the hurricane's eye moved over Guadeloupe with a barometric pressure of 940 mb (28 inHg), suggesting maximum sustained winds of 140 mph (230 km/h), or Category 4 intensity on the Saffir–Simpson scale. Continuing to the west-northwest, the hurricane passed about 10 mi (16 km) south of Saint Croix before approaching Puerto Rico. On September 13, the 15 mi (24 km) eye crossed Puerto Rico in eight hours from the southeast to the northwest, moving ashore near Guayama and exiting between Aguadilla and Isabela. A ship near the southern coast reported a pressure of 931 mbar (27.5 inHg), and the cup anemometer at San Juan reported sustained winds of 160 mph (257 km/h) before failing. As the wind station was 30 mi (48 km) north of the storm's center, winds near the landfall point were unofficially estimated as high as 200 mph (320 km/h). On this basis, the hurricane is believed to have made landfall in Puerto Rico as a Category 5 hurricane on the Saffir-Simpson scale, although there was uncertainty in the peak intensity, due to the large size and slow movement of the storm. After emerging from Puerto Rico, the hurricane had weakened to winds of about 140 mph (230 km/h), based on a pressure reading of 941 mbar (27.8 inHg) at Isabela. The storm brushed the northern coast of Hispaniola while moving west-northwestward, gradually restrengthening. On September 15, it passed within 35 mi (56 km) of Grand Turk, by which time the winds increased to 155 mph (249 km/h). The storm continued through the Bahamas as a strong Category 4 hurricane, passing near Nassau at 10:00 UTC on September 16.

Initially, Richard Gray of the U.S. Weather Bureau was optimistic that the storm would spare South Florida. However, at 00:00 UTC on September 17, the large hurricane made landfall in southeastern Florida near West Palm Beach, with estimated winds of 145 mph (233 km/h). This was based on a pressure reading of 929 mbar (27.4 inHg) in the city, which at the time was the lowest pressure reading in the mainland United States; this broke the previous record of 935 mbar (27.6 inHg) set during the 1926 Miami hurricane. Peak gusts were estimated near 160 mph (260 km/h) at Canal Point.

The hurricane quickly weakened as it progressed inland and moved over Lake Okeechobee, although its large size enabled it to maintain hurricane status for several more days. Late on September 17, the hurricane recurved to the northeast and passed near Jacksonville early the next day with winds of 75 mph (121 km/h). At 08:00 UTC on September 18, the storm again reached open waters. Later that day, the hurricane restrengthened slightly over open waters, making a second United States landfall near Edisto Island, South Carolina, at 19:00 UTC with winds of 85 mph (137 km/h). Accelerating northeastward, the system quickly weakened into a tropical storm over North Carolina. On September 19, the storm transitioned into an extratropical cyclone, although it restrengthened slightly to hurricane strength, due to baroclinic forcing caused by a frontal system. The cyclone turned to the north-northwest, moving quickly through the eastern United States. On September 21, the former hurricane dissipated over Ontario, having merged with another disturbance.

The hurricane moved directly over the Leeward Islands in the Caribbean Sea, strengthening as it did so. On the island of Dominica, winds were clocked at 40 mph (64 km/h). One person perished, while the cyclone also damaged seawalls and ruined crops. In Martinique, further south of the storm's path, there were three deaths. Waves washed away homes along the island's northwest coast, although a report by Walter S. Reineck, U.S. Consul in Martinique, noted that the worst damage occurred to cocoa, lime, and sugarcane crops.