London, Scotland, and Ireland (also Belfast)

Realistic? It's possible to do it. Enjoyable? Smart? Doesn't look like either to me, not with 13 days (and you should really detail exactly how many days you really have, not including arrival and departure days).

Remember, every time you pick up and move, that burns most (or all) of a day. So when you say X days here, Y days there, you need to subtract 1 from all those numbers. So you get 2 days in London, 2 days in Dublin - oops, no, one day in Dublin, less than one day in belfast, 3 days "Galway area", one day in Glasgow - oops, no, less than one day each in Glasgow, less than a full day in Edinburgh...

That looks like a punishing death-march to me.

Start by being honest with yourself: how many days do you have, not including arrival and departure days (no matter what time flights are scheduled)? However many days you have, you have three countries (four, actually, since Northern Ireland should count as one). I think you need to cut out one of them. Knock out either Scotland, or Ireland. Sad to say, Ireland does not look like a good fit here. Take (all of Ireland, the Republic and Northern Ireland) that out of the equation, and it starts to look more realistic. With 13 days, you can get a quick, but enjoyable, taste of some of the UK.

I'd start in London and work my way up to Edinburgh.

David has overstated the time you will get in each location, as he hasn’t allowed any transfer time.

If Ireland is important to you, then keep Ireland and drop Scotland, otherwise you are going to spend more time in transit than you are visiting places.

If you can fly open jaw into London and out of Dublin or vice versa, this will save a day back tracking.

I agree with Jennifer. With only 13 nights, since Ireland is your priority, go there. Can you get a flight in and out of Shannon? That's the nearest to Galway, though Dublin would also be convenient. You could fly open jaw Shannon-Dublin or vice versa.

This would not be enjoyable to attempt. You would be rushing around like crazy and have little time to enjoy yourself, and you would waste a lot of time catching trains or planes to get to the next city.. It seems that Ireland is what is important to you so if you haven’t bought you plane tickets yet then I would highly recommend that you do just Ireland for this trip. Two weeks would allow you to see all the things on your list at a much more reasonable pace. You could fly into Dublin and out of Belfast and save some time that way, also. Quite frankly, just three nights in London is almost not worth the trouble for a city that size with so much to see. You wouldn’t even scratch the surface and would have a hard time deciding what to see and what to bypass. Two weeks from London to Scotland would be a reasonable trip for two weeks, but even that would be a quick pace.

Thanks Everyone! Even for David's harsh wake up call.
Looks like we will cut Scotland out. We've been to London before and the one full day we are there would pick one thing to see that we haven't done before.

Would a day trip to Belfast be a good idea?

Are your flights booked? It sounds like you have a flight to London...also returning from there? If so, that raises the question: do you really want to go to London, or is your goal to go to Ireland? If it's the latter, consider this: what would it cost to dump your (presumably) already-booked flight to/from London, and switch to more efficient flights to/from Ireland. Take into account ALL the costs: the cost of the Ireland ticket versus the London ticket, whatever penalty or fee it takes to get out of the booked tickets and apply the payment to new/better tickets, also the cost savings by skipping London hotels, meals, etc. Then factor in the TIME saved by skipping London and going where you actually want to go (presumably Ireland). Weigh it all. Maybe it makes more sense to keep your existing flights, maybe not, but you won't know which to choose until you figure out what it would cost (or save) to switch. That's just how I'd approach it...

I very much enjoyed our day in Belfast. The Titanic exhibit was extremely well done.

Sadly, my least favorite location on our trip was Galway. I know you said there was a connection for you, but I wouldn’t spend that much time there.

Agree with everyone (and I think you got the idea - ha!). If you can’t change your London flights AND you have been to London before, you might consider just having one full day there (2 nights), as well as the night before your flight home, and give all your other nights to Ireland. That would allow you one more night in Ireland, maybe for Belfast, if that is also a priority.

Thanks all,

We got a good deal on British Airways tickets nonstop from SJC to LHR, like $830 for two tickets! This was significantly less than the tickets from SJC to DUB.

The current plan is to get our tickets from LHR to DUB the same day we arrive at LHR. And possibly visit London a couple of days before we fly back home.

We are hoping to rent a car and explore the country by car. The prices are significantly expensive for one way car rentals so the current plan is to pick up and drop off the car in Dublin and fly back from there to LHR. Would a train be better when we explore Belfast for a day trip?

Cheers!

The current plan is to get our tickets from LHR to DUB the same day we arrive at LHR.

Why is that?

Have you priced last-minute tickets from LHR to DUB? I have not checked this route specifically, but as a general rule, waiting until the day of travel usually causes the price of tickets to go up astronomically (like, up to 10X), so I would definitely not plan on that. If you buy your flight far in advance, you will almost certainly get a much, much better price. I'd suggest you check what it costs for a last minute ticket today, you may find it costs as much as your flight from SJC or more. FWIW, last summer I priced a same-day short intra-Europe ticket (due to a scheduling snafu) - that ticket which cost $100 if purchased well in advance was priced at over $1500 when purchased the day of travel.

As a general rule, travelers are rarely rewarded for waiting until the last minute to buy anything. There are exceptions, but it's not a safe bet.

I intend to buy tickets in advance.