 Inland areas are warmer in summer and colder in winter . Usually around 40 days of the year are below freezing 0 ° C ( 32 ° F ) at inland weather stations , compared to 10 days at coastal stations . Ireland is sometimes affected by heat waves , most recently in 1995 , 2003 , 2006 and 2013 . In common with the rest of Europe , Ireland experienced unusually cold weather during the winter of 2009 / 10 . Temperatures fell as low as − 17 @.@ 2 ° C ( 1 ° F ) in County Mayo on 20 December and up to a metre ( 3 ft ) of snow fell in mountainous areas . 
