All mean air temperatures for Autumn were above normal, with differences above average ranging from 1°C at Cork Airport to 2.2°C at Casement Aerodrome. All three months of the season recorded higher than normal temperatures, with November having the greatest differences above average. Most stations in the east and midlands reported Autumn 2011 as the warmest on record, with Phoenix Park reporting an Autumnal mean temperature of 12.2°C, its warmest in over 150 years. Mean air temperature differences in the south and southwest were less, but it was still the warmest in a number of years at Shannon Airport and Roche’s Point, both recording their warmest Autumns since 2001 (10 years) and 2006 (5 years), respectively. All remaining Atlantic coastal stations were above average for the season, but were not as warm as the Autumn of 2007.
All highest maximum air temperatures for Autumn were recorded during September, with the majority measured on the 28th. The highest temperature was recorded on this date at Phoenix Park with 25.6°C, the highest temperature recorded at a synoptic station in 2011 and the highest Autumn temperature recorded at the site since Autumn 2003 (8 years). Lowest minimum air temperatures for Autumn were all recorded during November, with the majority of stations in the south and southwest reporting their highest ever autumnal minimum temperatures. Belmullet and Valentia Observatory reported minimum temperatures of 4.0°C and 2.9°C, the warmest minimum temperatures recorded during the Autumn months since 1956 (55 years) and 1939 (72 years), respectively.
Rainfall totals for Autumn were above normal in most parts, except for some stations in the south and southeast. Above average rainfall was experienced almost everywhere during September and October, with below normal rainfall in a few eastern and coastal locations in November. Dublin Airport reported its wettest Autumn since 2002 (9 years) and Belmullet reported its wettest autumn since 2006 (5 years) with 134% of its long-term average. The highest daily fall of the season of 82.2mm at Casement Aerodrome on the 24th October, was its highest daily fall during Autumn, since it opened in 1964 (47 years). Even though totals were below normal in some parts, the number of wetdays (days with 1 mm or more) recorded across the country was above average for Autumn.
Sunshine totals for Autumn were below normal, with November being the only month to record above average sunshine for the time of year. All stations reported the dullest Autumn in a number of years, with Cork Airport and Valentia Observatory recording their dullest Autumns since 1962 (49 years) and 1983 (28 years), respectively. Dublin Airport received the highest total sunshine for the season, recording over 279 hours of sunshine and 94% of its longterm average, but it was still the dullest Autumn since 1993 (18 years).
Mean windspeeds for the season were mostly above average, with Dublin Airport reporting the highest mean windspeed for Autumn since 1943 (68 years). The highest gust of the season was at Malin Head with 66 knots (122 km/h) on the 12th of September.
Source – Met Eireann