The 4.8km-long tourist retreat, with a population of around 100, experienced an average daily temperature of 12C during October.
The islanders are used to balmy Octobers — it was the warmest place to be in the same month last year.
Met Éireann found that last month was the driest October in at least five years, with temperatures above average almost everywhere.
Rainfall amounts were below average everywhere — all stations found that the monthly total was two thirds or below what would have been considered normal for the time of year.
Long-term average rainfall values ranged from 41% at Sherkin with 52.8mm to 64% at Mountdillon, Co Roscommon, with 71.2mm.
Valentia Observatory, Co Kerry, recorded the highest rainfall total at 96.1mm. It also experienced the wettest day, October 23, with 26.8mm.
Casement Aerodrome, Co Dublin, reported its wettest day of the month on October 24 with 7.7mm, its lowest recorded as an October wet day since 1992. The first day of last month was the sunniest October day on record for Casement Aerodrome since it opened in 1964.
Belmullet, Co Mayo, experienced the sunniest day with 11 hours of sunshine on October 1. It was just ahead of Casement Aerodrome with 10.2 hours.
The highest monthly sunshine total, at 118.3 hours, was recorded at Malin Head, Co Donegal. Knock Airport, Co Mayo, had the lowest monthly total at 75.9 hours.
The number of dull days — when there was less than half an hour of sunshine — ranged from seven at Casement Aerodrome to 12 at Valentia Observatory.
Knock Airport saw the lowest mean temperature at 9.7C. The warmest day, at 19.1C, was recorded at Oak Park, Carlow, on October 1.
The lowest air temperature at minus 2C, was recorded at Markree, Co Sligo, on October 17 and the lowest grass minimum temperature at minus 5.1C was recorded at Markree on October 15.
Monthly average mean wind speeds ranged from 9km/h at Moore Park in Fermoy, Co Cork, to 23km/h at Mace Head, Co Galway.
Newport, Co Mayo, reported its calmest October since 2005, with a monthly mean speed of 14km/h. Gale force winds were reported on October 6, 21, 22, and 26 in Atlantic coastal areas.
Malin Head experienced the month’s highest gust (102km/h) and highest 10-minute average wind speed (74km/h) on October 22.
New Yorkers Mikey Hoffert-Cone, Sophia Mark, and Anna Deery in St Stephen’s Green.