The best time to visit Ireland

What a year in Ireland looks like

Ireland has no temperature extremes, because the ocean keeps the winters mild and the summers cool. What genuinely changes through the year is wind and light: winter brings a steady Atlantic blow and darkness by late afternoon, while at midsummer the western sky never fully closes until nearly eleven at night. Rain here tends to arrive as short bright-then-grey cycles rather than as an all-day downpour, which is why locals keep walking regardless of the forecast. Plan for changeable rather than for wet.

The year, in windows

• March to April — The fields come back to a green so strong it explains the country's nickname, though the wind still carries a bite and fully open skies are not yet common. March holds the national day, when towns run parades and the pubs are fuller than at any other point in spring — look up the year's calendar whether you want to catch it or dodge it. Outside Dublin, rooms are still easy to find and the coastal drives are quiet. Some rural attractions run reduced hours until the season proper begins.
• May to June — People who know the island well tend to name these weeks as the best of the year. The light lengthens every week, wildflowers fill the hedgerows and stone walls, and the midsummer wave of visitors has not yet arrived. The narrow driving loops on the south-western peninsulas are not yet queued behind slow coaches the way they are in August. Most years this window also strings together the greatest number of genuinely dry days.
• July to August — The busiest and brightest stretch of the year. The famous cliffs and the western coastal route collect queues of people waiting for the same photograph, and narrow country lanes fill up behind camper vans and tour coaches. The compensation is real: boats to the small offshore islands run their fullest timetable of the year, and traditional music festivals in the small towns cluster into these two months. Book cars and island crossings well ahead rather than on the day.
• September to October — The shoulder that suits anyone allergic to crowds. September still has enough daylight for a full day out, while October brings bigger seas and the kind of dramatic, fast-moving sky that photographers travel for. Island ferries begin thinning their sailings from mid-October, and some village restaurants on the exposed coasts close until spring. Check opening times for anything remote before driving two hours to reach it.
• November to February — A season for pubs, live music and museums. It rarely gets properly cold and city snow is unusual, but Atlantic storms arrive in waves and can cancel ferries and the occasional domestic flight. Daylight is short enough that any scenic drive has to be squeezed between mid-morning and mid-afternoon. Prices are at their lowest and the cities feel entirely local, which is the trade for losing the long evenings.

The weeks to aim for

The sweet spot runs from late May into early July, and then again through September. Those weeks give enough daylight to drive a whole peninsula loop in a day, deliver as many dry days as this island ever manages, and leave you not fighting a coach for every viewpoint car park. Anyone hoping to reach the small western islands should stay inside that frame, because the ferry timetable is complete and cancellations for heavy swell are least likely. September has the added advantage of warmer sea temperatures than June, if swimming is on the list.

The weeks to avoid

The stretch people most often regret is mid-November to mid-February, less for the cold than for the storm cycles and the short days that make a coastal itinerary barely workable. The country's finest drives run along exposed cliffs, and those are the first roads closed when the wind passes a certain strength. The other period to think twice about is the week around the national day in March, when pubs and city rooms fill at once; if you are not there for the celebrations you pay peak rates for an ordinary trip. Going anyway is fine, as long as the plan leans on towns, music and indoor places rather than on views.

What the season does to a data plan

Irish maps mislead people, because the distances are short but the roads are narrow and endlessly bent. In summer, when everyone is driving the western coastal route, you will hit stretches of several kilometres with no usable signal behind a ridge or down in a valley, so load the whole day's route before leaving town. Ferries to the small islands typically lose service mid-crossing and pick it up again near the pier, so confirm any island booking while you are still on the mainland. In winter the data moves indoors, into pubs and hotels with good Wi-Fi — but when a storm knocks out power in patches, the Wi-Fi goes down before the mobile network does, which makes a working mobile line more valuable in the windy months than most visitors expect.