The name Tammy has been used for two tropical cyclones worldwide, both in the North Atlantic Ocean.
The 2005 Atlantic hurricane season was the most active year on record until surpassed by 2020. It featured 28 tropical or subtropical storms. The United States National Hurricane Center named 27 storms, exhausting the annual pre-designated list, requiring the use of six Greek letter names, and adding an additional unnamed storm during a post-season re-analysis. A record 15 storms attained hurricane status, with maximum sustained winds of at least 74 miles per hour (119 km/h). Of those, a record seven became major hurricanes, rated Category 3 or higher on the Saffir–Simpson scale. Four storms of this season became Category 5 hurricanes, the highest ranking.
Tropical Storm Tammy was a short-lived tropical storm during October in the 2005 Atlantic hurricane season which caused minor damage to the southeastern United States. More significant, however, were its remnants, which contributed to the Northeast U.S. flooding of October 2005.
The 2005 Azores subtropical storm was the 19th nameable storm and only subtropical storm of the extremely active 2005 Atlantic hurricane season. It was not named by the National Hurricane Center as it was operationally classified as an extratropical low. It developed in the eastern Atlantic Ocean, an unusual region for late-season tropical cyclogenesis. Nonetheless, the system was able to generate a well-defined centre convecting around a warm core on 4 October. The system was short-lived, crossing over the Azores later on 4 October before becoming extratropical again on 5 October. No damages or fatalities were reported during that time. Its remnants were soon absorbed into a cold front. That system went on to become Hurricane Vince, which affected the Iberian Peninsula.
Hurricane Tanya was the first named storm to start with a "T" in the Atlantic since naming began in 1950, and the final storm of the very active 1995 Atlantic hurricane season. The twenty-first tropical cyclone, nineteenth named storm, and eleventh hurricane of the season, Tanya developed from a tropical wave while well north of the Lesser Antilles on October 26. The system headed northeastward and strengthened into Tropical Storm Tanya on October 27. Tanya meandered around the central Atlantic, and further intensified into a hurricane on October 29. Thereafter, Tanya tracked northeastward before curving to the east-northeast. After switching to an eastward direction, Tanya weakened to a tropical storm on November 1. Later that day, Tanya passed through the Azores as it was transitioning into an extratropical cyclone.