April - May
April and May are considered part of the `shoulder season` in Ireland. The phrase `April showers bring May flowers` is very true in Ireland. If you arrive too early in the month of April, you will most likely be caught in a few rain storms as the rainy season draws to a close. By May, the rainfall will have moderated, and temperatures will rise. If you arrive in April, expect temperatures to be in the 40s Fahrenheit in the mornings and 50s in the afternoons. By May, temperatures will rise into the low 60s during the day and fall into the upper 40s at night. Many attractions in the countryside may not open until the month of May, so keep that in mind when traveling outside the cities.
Holidays and Festivals:
Friday before Easter - Good Friday (Aoine an Chéasta). National holiday in the Republic of Ireland Northern Ireland.
Monday after Easter - Easter Monday (Luan Cásca). The day after Easter Sunday (Domhnach Cásca) -- also coincides with the commemoration of the 1916 Easter Rising, an insurrection against the then-ruling British crown. National holiday in the Republic of Ireland and Northern Ireland.
First Monday in May - May Day (Lá Bealtaine). Traditionally, villages would build bonfires as a way to welcome the long days and nights of summer. It is also observed as a day of honor and remembrance for workers and those who fought for workers` rights. National holiday in the Republic of Ireland. In Northern Ireland the holiday is observed as the `Early May Bank Holiday.`
May 16 - Feast Day of St. Brendan the Navigator, one of the `Twelve Apostles of Ireland`. Observances island-wide, including in St. Brendan`s home village of Fenit, County Kerry.
Late May - Fleadh Nua, Ennis, County Clare. A festival promoting Irish-language music, dance, and cultural activities.
Late May - The Biggest Weekend, Belfast. Presented by BBC Music and BBC Radio 6, it is one of the largest indie and pop music festivals in Ireland.
Late May and early June - Listowel Writers' Week, County Kerry. The oldest literary festival currently running in Ireland, it has brought Irish and international writers together in the town of Listowel every year since 1970.
Last Monday in May - Spring Bank Holiday. National holiday in Northern Ireland.