Eight weather stations recorded temperatures well above average for the season.
In the case of Mullingar, Co Westmeath (11.3 degrees mean temperature, 1.7 degrees above its long term average) and Claremorris, Co Mayo (11.3 degrees, 1.5 degrees above its long term average), it was the warmest autumn since records began 71 years ago.
The other stations that recorded record temperatures were Mace Head, Co Galway (records stretching back 13 years), Ballyhaise, Co Cavan (18 years), Athenry, Co Galway (11 years), Mount Dillon, Co Roscommon (16 years), Finner, Co Donegal (10 years) and Knock Airport (25 years).
The season’s highest temperature of 27.9 degrees was reported at both Shannon Airport, Co Clare (its highest maximum temperature for autumn on record – 75 years) and Valentia Observatory, Co Kerry (its highest maximum temperature for autumn since 1991), both on Tuesday, September 7th.
All weather stations had higher temperatures than normal. The highest deviation from the seasonal norm was in the Phoenix Park where the average temperature, 11.9 degrees, was 1.8 degrees above the long-term average.
Ireland stayed on the warmer, southern side of the jetstream through most of autumn.
High pressure to the south of Ireland dominated through much of September and November giving warmer and drier than average conditions, while low-pressure to the west of Ireland dominated through much of October, giving warmer and wetter than average conditions.
There were a few cooler periods when Ireland lay on the northern side of the jetstream, notably for a few days at the end of September and beginning of October, for a few days at the beginning of November and for several days towards the end of November.
During these periods, high pressure set up to the west of Ireland, allowing polar maritime air mas