Flight to Santorini

If all goes well, you should probably be fine. But things don't always go exactly as scheduled.

Would this be on a single ticket, or two separate tickets? Given the way you describe this (one ticket booked, the other not) sounds like two separate tickets.

If on one ticket, and you miss your connection, then they'll put you on the next available flight, so probably just extra hours waiting, no extra cost. When exactly is that next flight? Santorini is of course very popular, but it's late September and schedules start to thin out.

But if on two separate tickets, the risks (and consequences) go up. Big question to ask is, what happens if you miss your onward flight to Santorini? If the next flight is just a few hours later (and there's space available on that flight), then you have workable a plan B (find out how much a same-day ticket would cost though, it may shock you).

Personally, I like 3+ hours for connections these days, longer that that if the consequences of missing the connection are dire (or very expensive).

It all boils down to risks: how bad would it be if you miss your 2 hours 30 minute connection? How bad would it be if you have to kill several hours in the airport?

On separately booked flights or part of the same Chicago itinerary/ticket?

For me if separately booked would be way too close for comfort. You will have to land, get your bag, go through customs, then go back in line to check in the bag again, go through security, etc...

You may breeze through and get lucky with no lines but no way to know until on the ground that day. And waht if you miss the next flight, you would have to pay out of pocket for a later flight at likely a last minute premium.
Fault would be on you even if the flight delayed, lines long, etc...

if part of the same ticket, that would be plenty of time to make your connection and your checked bag would be handled by the airlines. Also if you miss the connection in this case the airline will cover added expenses.

From the time you give it looks as if you might be on American Airlines which is the Star Alliance group with Olympic/Aegean Airlines. Call American and see if they can book and add the flight to your current ticket. Immigration in Athens is usually quick and easy and if you do carryon even better and you should be OK as you would use the transit desk in the Customs Hall. And avoid the crowded departure area. If you cannot get your ticket changed go for a later flight, there are a lot ohoices, almost one flight an hour to Santorini by various airlines. Athens is not a bad place to linger between flights. Interesting food options, or go upstairs to the sit down restaurant, for something to eat, wander round the mini museum displaying the artifacts found when they built the new airport.

They are 2 separate tickets. Well... will be since I haven't booked the second yet. Was hoping for some realistic insight from you lovely people before stupidly booking and putting myself between a rock and a hard place. The ticket is not expensive, thankfully. I can book the afternoon flight for $20 more and it'll give me another 2 hours or so. I just keep hearing mixed things about how long it'll take to get through customs, get my luggage, and make it to my next flight. Some people are saying it's super fast other people are saying it could be a while so I came looking for a better answer here.

@Ianlubber I am flying American! I didn't know I could do that. I could always check, thanks for that tip!

on the 28th (next Tuesday)

Tuesday is the 27th.

AA does show a ORD-JTR ticket with 2h 5m layover, so theoretically a 2.5 hr layover would work.

A single ticket would be the better solution, so the burden/expense falls to the airline if the first flight is late.

No personal experience transferring at ATH; it was endpoint and origin for me. Worked well (pre covid)

With checked luggage I might do a later flight. You are going to have to pick up your luggage and then stand in line to recheck it. The airport is easy to navigate but the times I did unconnected flights I only had carry on.

Joe, sorry! I leave on Tuesday the 27th, I land on the 28th. I'm going to call AA and see if I can add on a flight

If you look at the statistics for your flight AA160 Chicago- Athens you will see that it is more often 15 to 30 minutes early than late. In fact it's almost never late with the exception of today's flight which departed 3h39 late from Chicago but was able to make up for this delay by arriving in Athens only 1h30 later than expected.

Knowing Athens airport if it was my flight I would keep the 10:30 Athens Santorini, if I was an anxious guy I would take the 11:10 with Aegean.

But as we say in France: "the advisers are not the ones who pay..."

I flew to Santorini on 2 separate tickets….DFW-ORD-ATH. I booked my flight ATH-JTR RT separately and I was able to make a change easily so I could arrive earlier to JTR. This was August 2019. I think 2.5 hours are enough…ATH is not a large airport.

Enjoy Santorini!

That should be plenty enough time. There’s a thread here a few weeks back that I read that was really informative. But let me share you my experience since this site and forum members have always been helpful. We booked two separate tickets…DTW-ATH (Delta) and ATH-JTR (SkyEspress)

Arrived at 1130 local in ATH on 22 Sep.
Passport Control—> pick up bags—>went upstairs to Departures area and checked in our bags at the SkyExpress counter for our 1400 flight to Santorini.

Bottom line is you’ll have enough time as long as you depart on time. Note that Skyexpress and Aegean lets you change your flights the same day with little to no penalties.

Safe travels.