Ireland gets waves year round. Summers like anywhere in Europe can result in prolonged flat spells, but there are swells at any time of the year. If you’re a novice then spring and summer is probably the time to go, as it’s a little warmer and there are loads of places to learn to surf in Bundoran and Lahinch especially.
If it’s good waves you want though, then the time to go is the autumn and into the early winter. September to December is best the water and air temperatures are still mild and the swell pumps out of the Atlantic.
There are three main areas to head to, Bundoran in County Donegal for its heavy reefs and big wave spots, Easky in Sligo for fun points and reefs and Co. Clare for big wave spots and heavy slabs. There is something for everyone in the winter in Ireland.