The cold May weather should become a thing of the past in the coming days as we finally start to see some warmer than average conditions. How warm is a bit uncertain but surely 20c is on the cards for Ireland. The last day we had a temperature that high was April 1st!! Since we have had nearly 2 months of cold weather.
June will start off warm 18 to 22c but then get more thundery as we move into the month. As long as the thunder is from the South the weather will remain warm. After 2 months of cooling it needs to stay over us a long time for temperatures to respond. Its uncertain what happens after mid June at this stage.
Maybe we get dragged into a brief cooler regime before it heats up again at the end of the month.