The average national temperature for December 2024 was 7.70 °C, which is 1.47 ° above the most recent 1991-2020 long-term average (LTA) and 1.78 ° above the 1961-1990 LTA.
According to the provisional climate statement for December 2024 from Met Éireann, the month was the 11th warmest December on record since 1900.
The warmest December on record was in 2015 with an average temperature of 8.56° and the coldest December was in 2010 with an average temperature of 1.44°.
Provisional gridded rainfall data suggests December 2024 averaged at 104mm (79% of the 1981-2010 LTA).
December weather data
December 2024 was mild and dry with pressure higher than normal overall. The month began with low pressure pulling away to the north-east followed by a transient area of high pressure giving a few cool days with some sunshine and frosty nights.
Atlantic low pressure took control for the second half of the first week. A deepening low pressure system, named Storm Darragh by the Met Office (UK), crossed over the northern half of the country late on Friday December, 6 and early Saturday, December 7.
This, along with high pressure to the west over the Atlantic pushing the isobars together, led to the windiest period of the month along with widespread rain, heavy in the north-west.
The second week was mostly dry and dominated by cool high pressure. Sunny spells early in the week gave way to more cloud as the week progressed.
The third week was mild with high pressure to the south initially bringing a few relatively dry days before low pressure approached from the south-west. This brought several weather fronts across the country with rain at times.
The week finished windy with a deep area of low pressure to the north and high pressure to the south. The fourth week began cool and windy before a mild airmass moved in from the south-west with high pressure to the south intensifying and pushing north.
It stayed mostly mild, relatively dry and cloudy for the remainder of the week, including the Christmas period. The month finished with a slow-moving weather front crossing the country from the north-west giving widespread rain, heavy in places.
Rainfall
All monthly rainfall totals across the country were below their 1981-2010 LTA. Percentage of monthly rainfall values ranged from 48% (70.8mm) at Mace Head, Co. Galway to 97% (133.5mm) at Belmullet, Co. Mayo.
Monthly rainfall totals ranged from 45.7mm (63% of its LTA) at Dublin Airport, Co. Dublin (its driest December since 2008) to 173.7mm (96% of its LTA) at Newport, Co. Mayo.
The highest daily rainfall total was 32.6mm at Belmullet, Co. Mayo on Friday, December 6 during Storm Darragh.
The number of rain days ranged from 15 days at Dublin Airport, Co. Dublin to 26 days at a few stations. The number of wet days ranged from eight days at a few stations to 23 days at Newport, Co. Mayo.
The number of very wet days ranged from one day at a few stations to five days at Valentia Observatory, Co. Kerry.
Dunsany, Co. Meath had its driest December since 2001. Three stations, Mace Head, Co. Galway, Mullingar, Co. Westmeath and Gurteen, Co. Tipperary had their driest December since 2010. Six stations in the south had their driest December since 2014.
Temperatures
All mean air temperatures across the country were above their LTA for the month. Deviations from mean air temperature ranged from 1.2° (8.6° mean temperature) at Roche’s Point, Co. Cork to 2.3° (7.8° mean temperature) at Finner, Co. Donegal.
Mean temperatures for the month ranged from 6.3° (2° above its LTA) at Knock Airport, Co. Mayo to 9.4° (1.4° above its LTA) at Sherkin Island, Co. Cork.
The month’s highest temperature was reported at Shannon Airport, Co. Clare on Tuesday, December 17 with a temperature of 15°.
Both the month’s lowest air and grass minimum temperatures were recorded on Tuesday , December 10 at Markree, Co. Sligo.
The lowest air minimum was -5.8° while the lowest grass minimum was -11.4°. More than half of stations reported ground frost.
The number of days with ground frost ranged from zero days at Roche’s Point, Co. Cork to 14 days at both Ballyhaise, Co. Cavan and Mullingar, Co. Westmeath.
More than half of stations reported air frost. The number of days with air frost ranged from zero days at Mace Head, Co. Galway to five days at a few stations.