The 1921 Atlantic hurricane season featured the most recent major hurricane to strike the Tampa Bay area in Florida. Although no "hurricane season" was defined at the time, the present-day delineation of such is June 1 to November 30. The first system, a tropical depression, developed on June 1, while the last, a tropical storm, dissipated on November 25. Of note, three of the twelve cyclones co-existed with another tropical cyclone during the season. 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 . 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. The season's activity was reflected with an accumulated cyclone energy (ACE) rating of 87, above the 1921–1930 average of 76.6. ACE is a metric used to express the energy used by a tropical cyclone during its lifetime. Therefore, a storm with a longer duration will have high values of ACE. It is only calculated at six-hour increments in which specific tropical and subtropical systems are either at or above sustained wind speeds of 39 mph (63 km/h), which is the threshold for tropical storm intensity. Thus, tropical depressions are not included here. Timeline Systems Hurricane One A westward-moving disturbance developed into a tropical depression over the western Caribbean Sea on June 16. About 24 hours later, the depression intensified into a tropical storm. Late on June 17, the storm made landfall in northern Belize with winds of . The cyclone moved northwestward and weakened slightly while crossing the Yucatán Peninsula, but remained a tropical storm. Early on June 18, the system emerged into the Gulf of Mexico and began to curve north-northwestward. Continuing to intensify, it attained hurricane status around 12:00 UTC on June 20. The hurricane drifted and strengthened further. Early on June 22,