LHR to ORD flight delays
London (LHR) Chicago, IL (ORD)
1,624 flights · January 2025 – August 2026 · UK Civil Aviation Authority and US Bureau of Transportation Statistics
78.63%
Arrived on time
Within 15 minutes of schedule
2.89%
Cancelled
Share of scheduled flights
—
When late, late by
Average across delayed arrivals
13 min
Delay per flight
Averaged over every flight flown
What the record says about this route
Which airline you fly changes the odds here. United Airlines arrived on time 18.8 points more often than British Airways over the same period on the same route — same airports, same weather, same air traffic control. A gap that survives all of that is about how the two airlines are run.
Cancellation, not delay, is the risk worth pricing here: 2.89% of scheduled flights never operated. A late flight still gets you there. A cancelled one leaves you rebooking, and on a route with few daily departures that can mean losing a day.
The two directions do not behave alike. ORD to LHR arrives on time 12.2 points less often than the outbound. Delay accumulates through the flying day, so whichever direction is scheduled later tends to carry the worse record — which is an argument for booking the morning departure if the choice exists.
The London to Chicago route sits close to the middle of the record — neither notably punctual nor notably late.
Which airline should you fly on this route?
Over January 2025 – August 2026, United Airlines arrived on time most often on LHR to ORD. British Airways was late most often. Flights ran closest to schedule in February and worst in March.
Every airline on LHR to ORD
Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.
| Airline | Flights | On time | Cancelled | Avg delay | Grade |
|---|---|---|---|---|---|
| American Airlines | 550 | 72.92% | 4% | — | D |
| United Airlines | 543 | 90.77% | 2.21% | — | A |
| British Airways | 531 | 72.01% | 2.45% | — | D |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
ORD to LHR Chicago back to London 66.43% on time FOther routes from London
Common questions
Are flights from London to Chicago usually delayed?
78.63% of flights on the LHR to ORD route arrived within 15 minutes of schedule, so roughly 2 in every ten arrived late. That is about the same as the average route in this record.
Which airline is most on time from London to Chicago?
United Airlines, at 90.77% on time across 543 flights. The least punctual on the route was British Airways at 72.01%.
How often are LHR to ORD flights cancelled?
2.89% of scheduled flights did not operate — about 29 in every thousand. That is high enough that cancellation, not delay, is the risk worth planning around.
What is the best month to fly London to Chicago?
February, when 88.4% of flights arrived on time. The worst was June at 73%.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on LHR to ORD during January 2025 – August 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.
A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.
Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →