Route reliability record
LAX→ORD
Los Angeles to Chicago
- Flights
- 7,119
- Period
- September 2025 to August 2026
- Distance
- 1,744 mi
- Carriers
- 5
This route lands a B, about a point worse than the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That rests on 7,119 LAX to ORD flights, of which United Airlines flew 3,414 at 79.9% on time.
Best time to fly LAX to ORD: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 89.0% of the time and Tuesday flights 81.6%, against 76.4% for the route overall.
The US average over the same twelve months is 77.3%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
76.4%
Arrivals under 15 minutes late, of 6,948 completed flights
Avg delay
84 min
Across delayed arrivals only, not all flights
Cancelled
1.39%
National rate is 1.89%
Best carrier
United
79.9% on time across 3,414 flights
These figures cover 7,119 flights between September 2025 and August 2026. Beyond the headline rate, 9.5% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on LAX to ORD
The choice of carrier is not cosmetic here. United Airlines arrives on time 79.9% of the time; American Airlines manages 73.9%. Sample sizes sit next to every figure, because a two-point gap across 3,091 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 3,414 | 79.9% | 69 min | 0.70% | B+ |
| Spirit Airlinesthin sample | 132 | 78.9% | 107 min | 6.06% | B− |
| American Airlines | 3,091 | 73.9% | 92 min | 1.78% | C |
| Delta Air Linesthin sample | 238 | 70.0% | 66 min | 0.00% | C+ |
| Frontier Airlinesthin sample | 244 | 62.3% | 135 min | 4.92% | D− |
United leads American by 6 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
Flights on LAX to ORD
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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Best ways to make this trip
The most reliable ways to fly Los Angeles to Chicago
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 3 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. LAX → ORDLos Angeles to Chicago | United Airlines | 79.3% | 79.9% | 0.70% | 5am–8am, Tue | UA 1941 07:00 |
| 2. SNA → ORDSanta Ana to Chicago | United Airlines | 77.1% | 77.4% | 0.38% | 5am–8am, Tue | — |
| 3. LAX → MDWLos Angeles to Chicago | Southwest Airlines | 76.3% | 76.7% | 0.55% | 5am–8am, Sat | — |
| 4. SNA → ORDSanta Ana to Chicago | American Airlines | 74.8% | 76.1% | 1.69% | 5am–8am, Tue | AA 2590 07:45 |
| 5. LAX → ORDLos Angeles to Chicago | American Airlines | 72.6% | 73.9% | 1.78% | 5am–8am, Tue | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 23 points, against 6 points between the best and worst carrier.
- 5am–8am1,118 flights89.0%
- 8am–11am1,446 flights76.6%
- 11am–2pm1,115 flights66.1%
- 2pm–5pm822 flights66.8%
- 5pm–8pm955 flights74.8%
- 8pm–5am1,663 flights80.1%
Scale runs 60% to 95%.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 66.1% on time against 89.0% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8pm–5am window is the busiest, with 1,663 flights scheduled in it.
Explore
Filter LAX to ORD by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On LAX to ORD, the best departure window is 5am–8am at 89.0% on time and the worst is 11am–2pm at 66.1%, a wide gap of 22.9 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am89.0%
- 8–11am76.6%
- 11am–2pm66.1%
- 2–5pm66.8%
- 5–8pm74.8%
- 8pm–5am80.1%
best all US flightsScale 60% to 95%.
Across the year
When delays peak on this route
This route's year swings by 14 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
Delays peak in March, when the on-time rate falls to 69.4%. February is the strongest month at 83.4%. Moving a flexible trip across that boundary buys 14 points. August was the busiest month here, with 762 flights.
Across the week, Tuesday is the strongest day at 81.6% on time and Sunday the weakest at 71.4%, a spread of 10 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 42% of the 138,000 delay minutes carriers reported here, and the remaining four split what is left.
- 42%Late-arriving aircraft
- 29%Carrier
- 28%National Airspace System
- 1%Extreme weather
- 0%Security
42% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 138,000 reported delay minutes here, that single category outweighs weather by 39 to one. The split is drawn from 137,806 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 89.0% on time here.
Cancellations sit at 1.39% against a national 1.89%, which is ordinary. Diversions add another 1.01%.
Connections and stage length
What a delay here actually costs
9.5% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 1,744 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 72.0% on time across 7,121 flights, 4 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 4 points of difference.
The sample behind these figures is 7,119 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in ORD after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 83.4% on time and March 69.4%, a swing of 14 points. If the dates move at all, move them out of March before you think about anything else. 6,948 completed flights over 12 months sit behind that.
Common questions
LAX to ORD questions
How often is LAX to ORD delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.6% of the 7,119 flights in this analysis, against 22.7% nationally. Delayed flights are late by an hour and a half on average.
Which airline is most reliable on LAX to ORD?
United Airlines leads at 79.9% on time across 3,414 flights. American Airlines is at the other end on 73.9%, a gap of 6 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on LAX to ORD?
The 5am–8am departure window is the strongest at 89.0% on time. The 11am–2pm window is the weakest at 66.1%, 23 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are March delays on LAX to ORD?
March is the weakest month at 69.4% on time, compared with 83.4% in February. Across the year that is 14 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- ORD to LAX — the return legseparate record
- Los Angeles International (LAX) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- United Airlines on LAX to ORD79.9%
- Spirit Airlines on LAX to ORD78.9%
- American Airlines on LAX to ORD73.9%
- Delta Air Lines on LAX to ORD70.0%
- Frontier Airlines on LAX to ORD62.3%
- LAX to SFO, a related route60.1%
- LGA to ORD, a related route66.7%
- LAX to JFK, a related route77.5%
- United Airlines on-time record79.9%
- Spirit Airlines on-time record78.9%
- American Airlines on-time record73.9%
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
Direction matters. LAX to ORD and ORD to LAX are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.