The official Atlantic Hurricane Season, which includes the Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico, is from June 1 to November 30. The season peaks between August and October, with September 10 as the day you're statistically most likely to find a tropical cyclone somewhere in the Atlantic basin.
Why?
The answer has to do with both wind and water.
Wind shear is the variation of the wind's speed or direction over a short distance within the atmosphere. Stronger wind shear in the spring fades through June and July, and by late August, wind shear reaches a minimum.
Hurricanes start with the evaporation of warm seawater, which pumps water into the lower atmosphere. This humid air is then dragged aloft when converging winds collide and turn upwards. At higher altitudes, water vapor starts to condense into clouds and rain, releasing heat that warms the surrounding air, causing it to rise as well. As the air far above the sea rushes upward, even more warm moist air spirals in from along the surface to replace it.
The number of hurricanes drops in late October and November. As fall temperatures arrive, wind shear increases in the Atlantic basin. The air and the water both cool down, resulting in fewer areas where the storms can form.
And only then we can breathe a sigh of relief — at least until next hurricane season.
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