Of the season 's twelve tropical cyclones , seven became tropical storms and five strengthened into hurricanes . Furthermore , two of these strengthened into a major hurricane — Category 3 or higher on the modern-day Saffir – Simpson hurricane wind scale — the most since the 1917 season . The strongest hurricane of the season , Hurricane Six , peaked as a low-end Category 4 with winds of 140 mph ( 220 km/h ) . Throughout Florida , the hurricane left about $ 10 million ( 1921 USD ) in damage and eight deaths . Two other cyclones left extensive impacts . Although not a tropical cyclone at the time , the remnants of the second hurricane contributed to a devastating flood in the Greater San Antonio area of Texas , which resulted in $ 19 million in damage and 215 fatalities . The third hurricane left thousands homeless in the Lesser Antilles and caused at least 81 deaths
a devastating flood
September 1921 San Antonio floods
1921 Atlantic hurricane season