Carrier route record
UASFO→LAX
United Airlines · San Francisco to Los Angeles
- Flights
- 3,335
- Period
- September 2025 to August 2026
- Share of route
- 29%
- Carriers
- 8
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on SFO to LAX lands a B+, level with the national rate of 77.3%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by roughly 45 minutes on average. That rests on 3,335 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 2,513 at 72.9% on time.
The US average over the same twelve months is 77.3%, so there is little to separate United on SFO 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
77.7%
Arrivals under 15 minutes late, of 3,330 completed flights
Avg delay
46 min
Across delayed arrivals only, not all flights
Cancelled
0.15%
National rate is 1.89%
Whole route
70.9%
Every carrier on SFO to LAX, 11,437 flights
These figures cover 3,335 flights between September 2025 and August 2026. The median arrival is 3 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Carrier by carrier
United against every carrier on SFO to LAX
United flew 3,335 of the 11,437 flights on SFO to LAX, about 29% of it. Its 77.7% on time is 7 points better than the route as a whole, which runs 70.9%. Ranked by on-time rate it is first of eight carriers on the route, where the range runs from United at 77.7% to Envoy at 0.0%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 72.9% of the time; Southwest Airlines manages 56.7%. Sample sizes sit next to every figure, because a two-point gap across 1,472 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines (this page) | 3,335 | 77.7% | 46 min | 0.15% | B+ |
| American Airlinesthin sample | 303 | 76.2% | 100 min | 0.00% | B+ |
| SkyWest Airlines | 2,513 | 72.9% | 61 min | 1.07% | C |
| Delta Air Lines | 2,373 | 69.8% | 63 min | 1.56% | C |
| Frontier Airlines | 394 | 66.5% | 77 min | 1.52% | C |
| Alaska Airlines | 1,046 | 66.4% | 47 min | 0.86% | C+ |
| Southwest Airlines | 1,472 | 56.7% | 62 min | 0.68% | D+ |
| Envoy Airthin sample | 1 | 0.0% | 35 min | 0.00% | F+ |
The spread between SkyWest and Southwest is 16 points, wide enough that it should decide the booking. On a hundred trips that is 16 more arrivals inside the on-time window.
Flight by flight
United flight numbers on SFO to LAX
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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 16 points between the best and worst carrier.
- 5am–8am477 flights92.5%
- 8am–11am640 flights80.4%
- 11am–2pm442 flights76.2%
- 2pm–5pm506 flights73.3%
- 5pm–8pm712 flights77.3%
- 8pm–5am558 flights67.6%
Scale runs 60% to 100%.
Book the early departure. Flights leaving between 5am–8am arrive on time 92.5% of the time, against 67.6% for the overnight window. That is 25 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 712 flights scheduled in it.
Across the year
United on SFO to LAX through the year
August is the worst month at 68.8% on time, 20 points below March, the best at 89.0%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. August was the busiest month here, with 304 flights.
Across the week, Tuesday is the strongest day at 83.0% on time and Thursday the weakest at 72.2%, a spread of 11 points.
Arrival by arrival
How late United on SFO to LAX runs when it is late
The 742 late arrivals split 334 under half an hour, 241 between 30 and 60 minutes, and 167 an hour or more.
- 15+ min early623 flights18.7%
- Within 15 min1,965 flights59.0%
- 15–29 min late334 flights10.0%
- 30–59 min late241 flights7.2%
- 1–2 hours late126 flights3.8%
- 2+ hours late41 flights1.2%
Scale runs 0% to 100%.
Share of 3,330 completed flights by arrival against schedule.
106 of 633 late departures made up the time and arrived on time, 17% of them. In the other direction, 215 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at LAX.
The worst days
Worst days for United on SFO to LAX
The latest arrival of the period was on 8 May 2026, 4 hours 57 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 8 May 2026 | 4 hours 57 minutes | Late-arriving aircraft |
| 30 December 2025 | 4 hours 41 minutes | Late-arriving aircraft |
| 2 January 2026 | 4 hours 12 minutes | Late-arriving aircraft |
| 9 June 2026 | 4 hours 5 minutes | Late-arriving aircraft |
| 5 January 2026 | 3 hours 48 minutes | Late-arriving aircraft |
Delay causes
Why United runs late on this route
Late-arriving aircraft accounts for 51% of the 34,000 delay minutes carriers reported here, and the remaining four split what is left.
- 51%Late-arriving aircraft
- 26%Carrier
- 22%National Airspace System
- 0%Extreme weather
51% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 34,000 reported delay minutes here, that single category outweighs weather by 51 to one. The split is drawn from 34,317 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 92.5% on time here.
Cancellations are rare at 0.15%, below the national 1.89% 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
5.0% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 45 minutes, which a normal layover absorbs.
At 337 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 62.9% on time across 3,330 flights, 15 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 15 points of difference.
The sample behind these figures is 3,335 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 SFO to LAX
Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 89.0% on time and August 68.8%, a swing of 20 points. If the dates move at all, move them out of August before you think about anything else. 3,330 completed flights over 12 months sit behind that.
Related
Where to go next
- SFO to LAX, every carrier
- United on LAX to SFO, the return leg
- American Airlines on SFO to LAX76.2%
- SkyWest Airlines on SFO to LAX72.9%
- Delta Air Lines on SFO to LAX69.8%
- Frontier Airlines on SFO to LAX66.5%
- Alaska Airlines on SFO to LAX66.4%
- Southwest Airlines on SFO to LAX56.7%
- United Airlines network-wide record
- San Francisco International (SFO) delay statistics
- Los Angeles International (LAX) delay statistics
- Why the first flight of the morning is statistically safest
- Same route, different airline: where the carrier you pick matters most
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.