Climate of Ireland

Köppen climate types in Ireland.
A typical North Atlantic low-pressure area moving across Ireland.

The climate of Ireland is mild, humid and changeable with abundant rainfall and a lack of temperature extremes. Ireland's climate is defined as a temperate oceanic climate, or Cfb on the Köppen climate classification system, a classification it shares with most of northwest Europe.[1][2] The island receives generally warm summers and cool winters.

As Ireland is downwind of a large ocean, it is considerably milder in winter than other locations at the same latitude, for example Newfoundland in Canada or Sakhalin in Russia. The Atlantic overturning circulation, which includes ocean currents such as the North Atlantic Current and Gulf Stream, releases additional heat over the Atlantic, which is then carried by the prevailing winds towards Ireland giving, for example, Dublin a milder winter climate than other temperate oceanic climates in similar locations.[3]

The prevailing wind blows from the southwest, breaking on the high mountains of the west coast. Rainfall is therefore a particularly prominent part of western Irish life, with Valentia Island, off the west coast of County Kerry, getting almost twice as much annual rainfall as Dublin on the east (1,400 mm or 55.1 in vs. 714 mm or 28.1 in).

January and February are the coldest months of the year, and mean daily air temperatures fall between 4 and 7 °C (39.2 and 44.6 °F) during these months. July and August are the warmest, with mean daily temperatures of 14 to 16 °C (57.2 to 60.8 °F), whilst mean daily maximums in July and August vary from 17 to 18 °C (62.6 to 64.4 °F) near the coast, to 19 to 20 °C (66.2 to 68.0 °F) inland. The sunniest months are May and June, with an average of five to seven hours sunshine per day.[4] Though extreme weather events in Ireland are comparatively rare when compared with other countries in the European continent, they do occur. Atlantic depressions, occurring mainly in the months of December, January and February, can occasionally bring winds of up to 160 km/h or 99 mph to Western coastal counties, with the winter of 2013/14 being the stormiest on record.[5] During the summer months, and particularly around late July/early August, thunderstorms can develop.[6][7][8]

  1. ^ Peel, M. C.; Finlayson B. L.; McMahon, T. A. (2007). "Updated world map of the Köppen–Geiger climate classification". Hydrol. Earth Syst. Sci. 11 (5): 1633–1644. Bibcode:2007HESS...11.1633P. doi:10.5194/hess-11-1633-2007. ISSN 1027-5606. (direct: Final Revised Paper)
  2. ^ "Marine Climatology". Met Éireann. Retrieved 30 January 2008.
  3. ^ McCarthy, G. D., Gleeson, E. and Walsh, S. (2015) The influence of the Ocean on the Climate of Ireland. Weather. 70, 8, 242–245, http://onlinelibrary.wiley.com/doi/10.1002/wea.2543/abstract
  4. ^ "Sunshine in Ireland". Met Éireann. Retrieved 23 January 2008.
  5. ^ Matthews, T., C. Murphy, R. L. Wilby and S. Harrigan (2014) Stormiest winter on record for Ireland and UK. Nature Climate Change, 4, 738-740.
  6. ^ "Evidence of winter storms". Independent Newspapers. 10 September 2011. Retrieved 4 February 2016.
  7. ^ "Evidence of storms". Irish Examiner. 13 February 2014. Retrieved 4 February 2016.
  8. ^ "July Thunderstorm" (PDF). Met Éireann. Archived from the original (PDF) on 5 April 2016. Retrieved 4 February 2016.