Limerick's climate is Atlantic Irish — mild, wet, and windy. Summer highs sit in the high teens; winter lows in the low single digits, rarely below freezing. The wettest months are October to January; the driest, March to June.
The best months for a city visit are May, June, and September: long days, mostly dry, mild evenings. July and August are warmer but no drier, and the city is busier with summer holiday traffic. The European rugby Champions Cup tends to peak in November to January and gives the city — and the cost of a hotel — a separate rhythm. The Limerick Riverfest in early May, with food, music, and river events, is the most lively weekend of the year; the International Band Championship around St Patrick's Day in March is the other.