Thanks to the moderating effect of the Atlantic Gulf Stream, Ireland’s climate is relatively mild for its latitude, with a mean annual temperature of around 10°C. The temperature drops below freezing only intermittently during winter, and snow is scarce – perhaps one or two brief flurries a year. The coldest months are January and February, when daily temperatures range from 4° to 8°C, with 7°C the average. In summer, temperatures during the day are a comfortable 15° to 20°C. During the warmest months, July and August, the average is 16°C. A hot summer’s day in Ireland is 22° to 24°C, although it can sometimes reach 30°C. There are about 18 hours of daylight daily during July and August and it’s only truly dark after about 11pm.
One thing you can be sure of about Irish weather is how little you can be sure of. It may be shirtsleeves and sunglasses in February, but winter woollies in March and even during the summer.
And then there’s the rain. Ireland receives a lot of rain, with certain areas getting a soaking as many as 270 days of the year. County Kerry is the worst affected. The southeast is the driest, enjoying a more continental climate.
When to go
The Irish weather works on the ‘four seasons in a day’ principle, which basically means that you can’t predict a thing when it comes to the behaviour of the sky. Some basic assumptions, however, can be made.
In summer, from May to July, the days are reasonably warm and – most importantly – very long: at the height of summer you won’t need to turn on lights until after 10pm. It is also peak tourist season, which means there are far more people just about everywhere but the most remote corners of the island, and prices are at their highest. Not surprisingly, most of the yearly festivals occur during these times so as to take advantage of the crowds and the more favourable weather.
Spring (February to April) and Autumn (August to October) make good alternatives, although the country’s ever-growing popularity as a tourist destination can often blur the lines between mid- and high-season tourism. Still, you have a better chance of some peace and quiet, and the weather can be surprisingly better in April and September than in mid-July – again, it’s all part of the uncertainty principle. Spring festivities include the ever-popular St Patrick’s Festival.
Although temperatures will barely venture below freezing, winter (December to February) can be brutal, but huge parts of the country – the west and northwest in particular – are at their savage and beautiful best in the cold winter light. Crowds are at their thinnest, but many of the country’s tourist attractions and services close down in October and don’t reopen until Easter, which paradoxically leaves visitors with a more convincing taste of how Ireland is experienced by most of the Irish: it’s cold, grey and dark by 5pm, but there’s always a pub to escape into when the rain starts sheeting down.