We all love a nonstop flight, and it’s definitely the way to go if it’s available. But more often than not, your flight (especially long-haul) is going to involve a connection somewhere. So when planning, it’s not just about looking at your departing airport, but where you are connecting.

There are some obvious red flags to avoid; for instance, if you’re flying in winter, try to avoid connections in snowy Chicago. But airports known for delays are another factor to consider. This summer, New York’s JFK is undergoing runway resurfacing, which means at any one time they’ll have only three of their four runways working. That airport is already known for delays, so expect more even more from April through summer, especially if the region experiences summer storms.

Does this mean you shouldn’t route through JFK this summer, or Chicago in winter? Not necessarily; just plan for potential delays by padding your connections with extra time, in case of delays. Better yet, book your flights (especially long-haul!) with a travel planner who can help you on the back end, rerouting you if you run into trouble. We charge $40 a ticket, which includes that service along with researching the best routes and fares. It’s well worth it when you run into trouble and can just call someone instead of joining the angry throngs lined up ten deep at the ticketing desk.