September combined spells of relatively dry, settled conditions with periods of very wet weather, giving some record-breaking daily falls of rain at some stations.
Temperatures were around two degrees higher than normal for most of the month, but cooler weather developed during the final week, bringing ground frost in some areas.
Monthly rainfall totals were above normal except in parts of Munster, with around twice the September average recorded in places; Mullingar had its wettest September since 1962. The number of wetdays during the month (days with 1mm or more rainfall) was close to normal, however, with almost all stations falling within the normal range for September of between 12 and 18 wetdays. Heaviest falls were measured in the period 5th to 7th and on the 9th, 13th and 22nd. Widespread daily falls of between 20mm and 60mm on the 6th were the highest on record for September at some stations: Knock Airport’s fall of 86.5mm on this day was the highest daily fall at the station for any month since rainfall measurements began there in 1988.
Mean monthly air temperatures were around one degree higher than normal and it was a particularly warm month in western areas. The highest daily values were measured during the first four days of the month, when maxima of over 20°C were widely recorded. In contrast, temperatures fell well below normal at times during the final week, when some very low air and ground temperatures for September were measured in midland and eastern areas.
Sunshine totals for the month were close to or a little higher than normal, with most stations recording their sunniest days in the period 1st to 4th. Source met Eireann
