Yes, hurricanes can occur in December, though they are exceptionally rare occurrences in the Atlantic basin. While the six-month Atlantic hurricane season officially concludes on November 30th, tropical cyclones occasionally develop outside this conventional window. The small number of these events confirms that December presents a significantly more hostile environment for tropical development compared to the peak months of August, September, and October.
The Climatological Constraints of Late Season Storms
Tropical cyclones require specific environmental conditions to form, primarily warm sea surface temperatures (SSTs) and low vertical wind shear. December storms are uncommon due to the seasonal shift in these atmospheric and oceanic factors. As winter approaches, SSTs across the main development region drop below the \(26.5^\circ\text{C}\) threshold needed to sustain deep convection.
The change in atmospheric circulation also introduces stronger vertical wind shear—the change in wind speed and direction with height. This strong shear tears apart developing low-pressure systems, preventing them from organizing into a tropical storm. Furthermore, the jet stream dips further south, introducing drier air into the tropical latitudes, inhibiting necessary thunderstorm activity.
For a December storm to form, a highly localized pocket of warm water is usually required, often found in the deep Caribbean Sea or the Gulf of Mexico. Any system that manages to develop in December tends to be short-lived due to the quickly changing, unfavorable conditions.
The Historical Record of December Hurricanes
Despite the challenging conditions, the historical record since 1851 shows that tropical cyclones have formed or persisted into December. Records indicate that 16 named tropical cyclones have had their genesis in December, and five of those intensified to reach hurricane status. This frequency illustrates how infrequently the necessary atmospheric alignment occurs after the official season ends.
One notable example is Hurricane Alice, which formed on December 30, 1954, and persisted into the following calendar year. Alice reached Category 1 hurricane strength, developing from a low-pressure area northeast of the Leeward Islands. Its existence spanning two calendar years highlights the extreme outliers in tropical cyclogenesis.
More recently, Hurricane Epsilon formed in the central Atlantic on November 29, 2005, and maintained hurricane status for five days into December, becoming the longest-lasting December hurricane on record. These rare December hurricanes are almost exclusively Category 1 intensity, with no storm recorded to exceed that strength in the month.