Winter in Ireland is relatively mild. There could be snow in the highlands and in mountains but the lowlands aren’t cold enough for the snow to stay. But frosty nights are common all around the country. The days are usually cloudy and rainy with occasional sunshine. January and February are the coldest months. Bring warm waterproof clothing since rainfall is common in winter as well. The days in winter are quite short with around 7-9 hours of daylight. But you can always spend the early evenings in cosy pubs sipping Irish whisky and chatting with the locals. And it’s off-season so there are no crowds, everything is cheaper and the main attractions are still available.