Be prepared! Here’s a cute 1 minute video by Tourism Ireland on the weather.
So what does that mean in October? The temperature will likely be between 45 and 70. And it will likely rain…not always but have your umbrella with you. Last year I spent almost three weeks traveling around Ireland and I think I had one day when it was misty (and one day when I had to scrape frost off the windshield). The year before it probably rained half the time I was there.
Dress in layers. It can be cold in the morning and warm up to a beautiful day in the high 60s (which may seem cold to you Florida people). The repositories can be warm or cold so have a sweater just in case.
Comfortable shoes are a must! We do a lot of walking. Also you need to be aware of uneven pavement and cobblestones which can be hard on the feet. And don’t forget to look in the opposite direction when you’re crossing the street. Remember in Ireland they drive on the opposite side. Wait for the walk lights and if you’re not sure…look down. Especially in Dublin, you’ll find a reminder.
The entire trip is casual. The final night’s dinner would be “business casual” which would be a nice pair of slacks or skirt and sweater for the women and a collared shirt and sweater or sports jacket for men (no tie required). Pack as light as possible, especially if you will be doing any traveling outside of the research trip. Lugging a big suitcase on a bus or train or up the stairs in a B&B can be tiring. (The hotels do have elevators, but Buswells is a group of row houses that have been put together and there can be stairs between different sections of the building.)
Hope this helps. Let me know if you have any questions.