The fifth month of the year, approximately equivalent to modern May, which followed the month of Víressë and was followed in turn by Nárië. Lótessë was the Quenya name for the month, while its Sindarin equivalent, favoured by the Dúnedain, was Lothron.
In the original King's Reckoning of Númenor, Lótessë would have run for thirty days from 22 April to 21 May, in modern terms. This remained the case until StewardMardil revised the calendar and inserted the feast-day of Tuilérë earlier in the year. In this Revised Calendar of the Stewards' Reckoning, then, Lótessë was still thirty days in length, but because of the insertion of Tuilérë it began one day later, running from modern 23 April to 22 May.
Lótessë was a spring month associated with the return of green growth after the winter, and its name comes from the blossoming of trees during this period. This connection with new growth is specifically referred to in an account of the sacred hallow on the Halifirien which, even at the height of summer, had the fresh green of the month of Lótessë.2
Lótessë was notable in history as the month in which the armies of the Eldar and the Edain set out to confront Morgoth in the closing years of the First Age (specifically, in the year I 472). In the story of Túrin's childhood, we are told of him watching his father Húrin depart on a bright spring morning in this month, as Húrin set out to join the forces gathered by High KingFingon. That hopeful march would end in the disaster of the Nirnaeth Arnoediad, and Túrin's farewell to his father on that morning in Lótessë would be the last time they would see one another.
Notes
1
These were all names used for the fifth month of the year in different calendars. In fact the exact timing of Lótessë varied by a few days across its history, so that none of these months are exactly equivalent in all eras.
2
This account comes from Unfinished Tales (Path Three II, Cirion and Eorl and the Friendship of Gondor and Rohan). In that tale, Cirion and Eorl reach the heights of the Halifirien (or Amon Anwar, the Hill of Awe, as it was then known). They reached the hallow in the high summer month of Úrimë, '...yet the crown of the Hill was green, as if the year were still in Lótessë.'