Weather for Southern Ireland?

My fiance and I will be spending our honeymoon in Ireland, arriving June 17 in Dublin and staying for 10 days.. We're travelling all around the southern and east coast, Waterford, Cork, Killarney, Limerick, Shannon, then back straight across with a stay on Offaly county and back to Dublin. We are currently packing, and we're unsure of what is really necessary. I love warm weather so anything less than 70 F i use sweaters, but we also plan totour and sightsee, and I know it gets hot walking around and such. Whats the daily average highs, and overnight lows? We'll be staying in bed and breakfasts along the way, so i'm wondering if they are heated at night, or if i should also pack warm pj's? Any help is appreciated, we want to finish shopping for our trip this weekend :D Thanks!