Carrier route record
UAORD→LAX
United Airlines · Chicago to Los Angeles
- Flights
- 3,380
- Period
- July 2025 to June 2026
- Share of route
- 49%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on ORD to LAX lands a B+, about a point worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 3,380 flights, with a median arrival 4 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate United on ORD to LAX from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
76.5%
Arrivals under 15 minutes late, of 3,355 completed flights
Avg delay
69 min
Across delayed arrivals only, not all flights
Cancelled
0.65%
National rate is 1.81%
Whole route
72.5%
Every carrier on ORD to LAX, 6,961 flights
These figures cover 3,380 flights between July 2025 and June 2026. Beyond the headline rate, 8.4% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
United against every carrier on ORD to LAX
United flew 3,380 of the 6,961 flights on ORD to LAX, about 49% of it. Its 76.5% on time is 4 points better than the route as a whole, which runs 72.5%. Ranked by on-time rate it is first of five carriers on the route, where the range runs from United at 76.5% to Delta at 60.6%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines (this page) | 3,380 | 76.5% | 69 min | 0.65% | B+ |
| Spirit Airlinesthin sample | 235 | 74.4% | 88 min | 3.40% | C− |
| American Airlines | 3,052 | 68.6% | 75 min | 2.29% | C |
| Frontier Airlinesthin sample | 228 | 66.4% | 75 min | 4.82% | C− |
| Delta Air Linesthin sample | 66 | 60.6% | 57 min | 0.00% | D+ |
Flight by flight
United flight numbers on ORD to LAX
Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 25 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am418 flights89.2%
- 8am–11am604 flights82.5%
- 11am–2pm513 flights83.6%
- 2pm–5pm864 flights74.0%
- 5pm–8pm426 flights64.0%
- 8pm–5am555 flights67.2%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 64.0% on time, against 89.2% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 2pm–5pm window is the busiest, with 864 flights scheduled in it.
Across the year
United on ORD to LAX through the year
January is the weak month at 67.7% on time, against 86.7% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 321 flights.
Across the week, Tuesday is the strongest day at 80.2% on time and Sunday the weakest at 71.6%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 42% of the 55,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 42%Late-arriving aircraft
- 32%Carrier
- 16%National Airspace System
- 10%Extreme weather
42% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 55,000 reported delay minutes here, that single category outweighs weather by 4 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 54,633 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 89.2% on time here.
Cancellations are rare at 0.65%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
8.4% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.
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 80.5% on time across 3,380 flights, 4 points above 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 3,380 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.
What to do with this
Booking United on ORD to LAX
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 86.7% on time and January 67.7%, a swing of 19 points. If the dates move at all, move them out of January before you think about anything else. 3,355 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to LAX, every carrier
- United on LAX to ORD, the return leg
- Spirit Airlines on ORD to LAX74.4%
- American Airlines on ORD to LAX68.6%
- Frontier Airlines on ORD to LAX66.4%
- United Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- Los Angeles International (LAX) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.