Why your return flight runs later than your outbound

The same route, flown the other way, is measurably worse. We checked every route in the record to see how often that holds.

Computed from 10,423,751 flights · January 2025 – August 2026 · recalculated whenever new data lands

A route is two routes. Los Angeles to New York and New York to Los Angeles share an aircraft type, an airline and a pair of airports, and travellers reasonably assume they share a reliability. Across 4,212 paired routes with enough flights to compare, 37% differ by five percentage points or more between the two directions.

The cause is the flying day. An aircraft that leaves late in the morning is still late in the evening, because a schedule with no slack cannot absorb the loss — so whichever direction is scheduled later in the day carries the accumulated delay of everything that went wrong before it. This is why a morning departure is worth more than a good airline.

The practical consequence is small and cheap: when a trip allows either, book the outbound early and accept the later return, rather than the reverse.

Route Outbound Return Gap
LTN ↔ LIS · Luton–Lisbon 77% 44.11% +32.9 pts
LIS ↔ LTN · Lisbon–Luton 44.11% 77% -32.9 pts
MDW ↔ PDX · Chicago–Portland 61.62% 89.07% -27.4 pts
PDX ↔ MDW · Portland–Chicago 89.07% 61.62% +27.4 pts
MCO ↔ RSW · Orlando–Fort Myers 60.73% 83.66% -22.9 pts
RSW ↔ MCO · Fort Myers–Orlando 83.66% 60.73% +22.9 pts
MLA ↔ MAN · Valletta–Manchester 47.4% 69.11% -21.7 pts
MAN ↔ MLA · Manchester–Valletta 69.11% 47.4% +21.7 pts
TIA ↔ STN · Rinas–London 55.95% 75.94% -20 pts
STN ↔ TIA · London–Rinas 75.94% 55.95% +20 pts
CLT ↔ SFO · Charlotte–San Francisco 65.69% 85.62% -19.9 pts
SFO ↔ CLT · San Francisco–Charlotte 85.62% 65.69% +19.9 pts

The widest direction gaps in the record.

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