Summers in Dublin are very comfortable. It can be cool, wet, and cloudy. The average high temperature is 67 and the average low in summer is 54.
A copy of your important documents like your passport
Your Gallagher health insurance information
Change some US Dollars into Euros before you arrive or plan to use the airport ATM when you arrive. Take a card that doesn't charge international transaction fees.
One or more adapters and power converters for 220 volts (if your electronics are not already "dual voltage") - European outlets are different!
Click here for a general Pre-Departure Checklist for study abroad.