Most travelers chalk up a late flight to bad luck or bad weather, but federal on-time data tells a more specific story: some airports are structurally, repeatedly, dramatically worse at getting planes off the ground on schedule than others. A SmartAsset analysis of Bureau of Transportation Statistics data ranked 75 of the country’s largest airports by on-time percentage, and the gap between the best and worst performers is wide enough to change how you book a connection. Here’s where delays are most likely to wreck your travel day — and why.
The data behind the ranking
SmartAsset built its ranking from Bureau of Transportation Statistics on-time performance figures for July 2025, weighting the percentage of scheduled departures and arrivals that actually left or landed on time across 75 major U.S. airports. BTS is the Department of Transportation’s own data arm, and it’s the same underlying source that other outlets have used to visualize airport performance — meaning this isn’t a crowdsourced complaint list, it’s a direct read of what airlines report to the federal government every month.
1. Long Island MacArthur Airport (ISP) — 60.3% on-time
The lowest on-time rate of any major U.S. airport belongs to this smaller Long Island field. Limited runway capacity and a heavy reliance on a handful of regional carriers mean a single weather delay or crew shortage ripples through the schedule fast.
2. Reagan Washington National (DCA) — 62.1% on-time
DCA’s tight airspace, shared with military and government flight paths around the capital, and a runway configuration that can’t easily absorb backups make it one of the most delay-prone big-city airports in the country.
3. Nome Airport (OME) — 62.2% on-time
Alaska’s remote geography and volatile weather patterns put Nome in rare company: a small regional airport whose on-time struggles rival those of the nation’s busiest hubs.
4. Newark Liberty International (EWR) — 63.7% on-time
Newark’s chronic congestion problems have made national headlines for years. Tight runway spacing relative to nearby LaGuardia and JFK, combined with some of the busiest transatlantic traffic in the country, keeps it near the bottom of nearly every delay ranking.
5. Chicago O’Hare International (ORD) — 64.0% on-time
One of the world’s busiest airports by traffic volume, O’Hare’s sheer scale works against it — more flights moving through fewer usable runway configurations during peak hours means delays compound quickly, especially in winter weather.
6. Philadelphia International (PHL) — 64.9% on-time
Philadelphia shares East Coast airspace congestion with New York’s cluster of airports, and its runway layout limits how many planes can depart or land simultaneously during busy periods.
7. Dallas Fort Worth International (DFW) — 64.9% on-time
DFW’s massive footprint and high flight volume as a major hub make it especially vulnerable to Texas’s volatile spring and summer thunderstorm season, which can ground operations for hours at a time.
8. Buffalo Niagara International (BUF) and Bradley International (BDL) — 65.3% and 65.4%
Both Northeast airports round out the bottom ten, with harsh winter weather and connections through already-congested regional airspace dragging down their on-time rates.
What this means for booking your next trip
Roughly 662,000 flights operated across the U.S. in June 2025 alone, according to BTS’s own monthly performance reporting, and the airports at the bottom of this list aren’t outliers because of one bad month — they show up near the bottom of similar rankings year after year, largely because of structural issues like runway geometry, airspace congestion, and exposure to severe weather that don’t change season to season. If you’re booking a tight connection, routing through Newark, O’Hare, DCA, or DFW during peak summer or winter storm windows is a meaningfully bigger gamble than routing through a mid-size airport with more runway capacity relative to its traffic.
None of this means avoid these airports entirely — plenty of trips require them. But building in a longer layover, picking an earlier flight on a delay-prone route, or checking an airport’s historical on-time rate before booking a same-day connection can be the difference between a smooth trip and a missed one. The data updates monthly at BTS’s public dashboard, so travelers who want current numbers before a big trip can check the source directly rather than relying on gut feeling about which airports run late.
