Route reliability record
LAX→SAN
Los Angeles to San Diego
- Flights
- 2,441
- Period
- July 2025 to June 2026
- Distance
- 109 mi
- Carriers
- 2
This route earns a A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 2,441 flights, with a median arrival 7 minutes early.
Set against the rest of the country, this route's record is 9 points better than the US average of 77.6%. That gap is worth roughly 91 fewer late arrivals for every thousand flights.
Key figures
On time
86.7%
Arrivals under 15 minutes late, of 2,418 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
0.94%
National rate is 1.81%
Best carrier
SkyWest
86.5% on time across 2,253 flights
These figures cover 2,441 flights between July 2025 and June 2026. The median arrival is 7 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.
Carrier by carrier
Which airline is most reliable on LAX to SAN
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 Airlinesthin sample | 188 | 89.4% | 46 min | 0.00% | A+ |
| SkyWest Airlines | 2,253 | 86.5% | 65 min | 1.02% | A |
Departure window
The best time of day to leave
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 2,441 flights.
- 5am–8am1 flights—
- 8am–11am713 flights87.3%
- 11am–2pm86 flights83.7%
- 2pm–5pm337 flights85.4%
- 5pm–8pm644 flights84.6%
- 8pm–5am660 flights89.0%
Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 83.7% on time against 89.0% for 8pm–5am. 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 8am–11am window is the busiest, with 713 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 16 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.
December is the weak month at 77.4% on time, against 93.2% in April. 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. May was the busiest month here, with 224 flights.
Across the week, Tuesday is the strongest day at 92.5% on time and Friday the weakest at 82.4%. 10 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Carrier accounts for 45% of the 21,000 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.
- 45%Carrier
- 26%National Airspace System
- 19%Extreme weather
- 10%Late-arriving aircraft
Extreme weather accounts for 19% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 3.0 times the usual weather exposure. The split is drawn from 20,574 reported delay minutes.
The largest share of delay minutes, 45%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 9,223 of the 21,000 delay minutes reported here.
Cancellations sit at 0.94% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here actually costs
Badly late arrivals are rare here: only 3.9% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
At 109 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 8pm–5am window matters as much as it does.
The return leg runs 89.2% on time across 2,441 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 2,441 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 this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 93.2% on time and December 77.4%, a swing of 16 points. If the dates move at all, move them out of December before you think about anything else. 2,418 completed flights over 12 months sit behind that.
Common questions
LAX to SAN questions
How often is LAX to SAN delayed?
About one flight in eight arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 13.3% of the 2,441 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is LAX to SAN compared with the rest of the country?
86.7% of flights arrive on time here against a national 77.6%, a difference of 9 points in its favour. That is worth a A+ on this site's grading scale.
What time of day has the fewest delays on LAX to SAN?
The 8pm–5am departure window is the strongest at 89.0% on time. The 11am–2pm window is the weakest at 83.7%, 5 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 December delays on LAX to SAN?
December is the weakest month at 77.4% on time, compared with 93.2% in April. Across the year that is 16 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
- SAN to LAX — the return legseparate record
- Los Angeles International (LAX) delay statistics
- San Diego International (SAN) delay statistics
- United Airlines on-time record89.4%
- SkyWest Airlines on-time record86.5%
- Worst months to fly in the US, ranked by the data
- Late aircraft, weather, or the airline: what actually causes US flight delays
Direction matters. LAX to SAN and SAN to LAX are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.