The 1939 Atlantic hurricane season was the least active since 1930. The season had below normal activity, with only six tropical storms, of which three became hurricanes and one became a major hurricane, equivalent to Category 3 status or higher on the modern-day Saffir–Simpson scale. The first tropical cyclone formed on June 12, and the last dissipated on November 6. These dates are within the period of each year when most tropical cyclones form in the Atlantic basin. All of the storms affected land to some extent. The first two cyclones of the season made landfall along the coast of the United States, collectively causing only minor damage. Hurricane Five, the strongest of the year, peaked as a Category 4 hurricane, with maximum sustained winds of 140 mph (220 km/h) and a minimum atmospheric pressure of . It took a northeastern path through the western Atlantic, striking Bermuda on October 16. The fifth and final storm was a minimal hurricane that wrought damage throughout the western Caribbean Sea, most notably in Jamaica and Cuba. The season's activity was reflected with an accumulated cyclone energy (ACE) rating of 34 units, far below the 1931–1943 average of 91.2. 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 Tropical Storm One The first tropical storm of the season developed in the extreme western Caribbean Sea on June 12. Reports of the storm first came from the Mexican Weather Service office in Chetumal, Quintana Roo, and during the afternoon of June 12, vessels just offshore recorded squally conditions and choppy seas. The cyclone moved northward, parallel to the coast of Belize, before moving over the northeastern corner of the Yucatán Peninsula. It continued steadily northward through the Gulf of Mexico, slowly strengthening to a peak of 50 mph (85 km/h) on June 14 with a minimum central pressure of . An area of high pressure to the north caused the storm to execute a counter-clockwise loop. A trough of low pressure turned it back to the north, and the