The 2013-14 British Isles cyclone season included Cyclone Patrick, which was the most intense European windstorm in modern records. The season began on November 1, 2013, and it ended on May 1, 2014. However, the definition of a tropical cyclone season is different than a tropical cyclone year, which ran from July 1, 2013, to June 30, 2014. These dates conventionally delimit the timeframe when most European windstorms tend to affect Ireland and the United Kingdom. All of the season's 21 tropical cyclones existed within the season's boundaries, except Cyclone Ultan, which formed two days after the end of the season. Cyclone Aidan, the season's debut storm, formed on November 22 from the remnants of Atlantic Tropical Storm Melissa, while Ultan, the season's finale storm, dissipated on May 6.