Hurricane Flora is among the deadliest Atlantic hurricanes in recorded history, with a death total of at least 7,193. The seventh tropical storm and sixth hurricane of the 1963 Atlantic hurricane season, Flora developed from a disturbance in the Intertropical Convergence Zone on September 26 while located 755 miles (1,215 km) southwest of the Cape Verde islands. After remaining a weak depression for several days, it rapidly organized on September 29 to attain tropical storm status. Flora continued to quickly strengthen to reach Category 3 hurricane status before moving through the Windward Islands and passing over Tobago, and it reached maximum sustained winds of 145 miles per hour (233 km/h) in the Caribbean.

The 1963 Atlantic hurricane season was a slightly below average season in terms of tropical cyclone formation, with a total of ten nameable storms. Even so, it was also a notoriously deadly and destructive season. The season officially began on June 15, 1963, and lasted until November 15, 1963. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin. The first system, an unnamed tropical storm, developed over the Bahamas on June 1.