Ireland is set for a damp and changeable start to December, according to Met Éireann’s extended forecast.

The first week of meteorological winter will be dominated by Atlantic low pressure systems, bringing frequent spells of rain and showers. Rainfall is expected to be above average nationwide, while temperatures will be close to or slightly above normal due to a mild southwesterly airflow.

The unsettled pattern is likely to continue into the second week, with further rain and showers across the country. Rainfall totals are expected to remain slightly above average and temperatures will stay higher than normal.

By mid December, forecasters say confidence in the outlook decreases. A southerly airflow is likely, with high pressure over Europe exerting more influence. This should reduce rainfall amounts below average in most areas, though southern counties may see closer to normal levels. Temperatures are expected to remain slightly above average.

In the final week before Christmas, confidence remains low. Current indications suggest a mix of showers and dry spells. Rainfall will be drier than average in the north and wetter in the south. Temperatures are expected to return closer to seasonal norms.

Met Éireann’s seasonal outlook for December, January and February points to above average temperatures overall, trending between 0.5 and 1 degree higher than normal. Despite the mild signal, forecasters warn of a greater likelihood of cold spells compared with recent winters, with all winter hazards possible, especially in December. Rainfall signals are less certain, though the north and northwest may see slightly wetter conditions. Sea surface temperatures around Ireland are also running above average, sustaining the influence of mild Atlantic air.

The UK Met Office has issued a similar forecast. From December 4 to 13, successive low pressure systems are expected to bring showers and longer spells of rain, with western areas most exposed to heavy rainfall. Snowfall is possible over higher ground in the north and strong winds may feature at times. Temperatures are expected to be close to or slightly above average.

Through the middle of December, unsettled conditions are likely to persist, with further spells of rain and windy interludes. Western regions again face the wettest conditions. Later in the month there are hints of slightly less unsettled weather, though prolonged dry spells remain unlikely. Temperatures are expected to stay near or a little above average.