Ireland’s climate is governed by moist air from the Atlantic Ocean and the effects of the Gulf Stream. This means the temperatures are fairly mild, despite its northern latitude. The weather can be very changeable year-round, so expect a mixture of sunny conditions and rain. The winter period can see lengthy spells of rain or cloudy weather and no sunshine at all.
If you are looking to visit Dun Laoghaire during the warm months, then July and August have average temperatures of 15°C to 20°C. Rarely does the mercury climb much above this point except for odd days. The long summer days can be appealing, as it doesn’t get completely dark until around 23:00. You will get an average of six hours of sunshine, but don’t be fooled into thinking that the weather will remain settled.
Summers can be notoriously wet, with rainfall fairly consistent all year. Good weather in the mornings can soon deteriorate, leaving cloudy skies and rain by the afternoon. On the other hand, if the morning starts dull and wet, don’t lose hope, as it may be clear throughout the day.
The spring and fall are considered by many to be the best times to visit Dun Laoghaire, as the temperatures are pleasantly mild and the attractions free from crowd. Prices also tend to be a little cheaper than the peak summer months; however, check your dates carefully, as there are many festivals, cultural events and sporting fixtures when prices increase and availability can be scarce.
If you are here for more than a few days, then you will certainly experience some rain. Ireland has a lush and green countryside for a good reason. Be prepared for sunshine, showers and fine misty rain that can last for hours.
Dun Laoghaire doesn’t suffer from extreme weather between seasons, but winter can be an inhospitable time to visit. January and February are the coldest months with daily temperatures averaging from 4°C to 8°C. Major snowfalls are rare, but it can rain every day for weeks.