Carrier performance at one airport
DL→SAN
Delta Air Lines at San Diego International
- Departures
- 9,581
- Period
- September 2025 to August 2026
- Routes
- 7
- Rank here
- #1 of 8
Delta Air Lines at San Diego earns an 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 77.3%. When something does go wrong the average delay runs a little over an hour. That rests on 9,581 flights, of which Delta Air Lines flew 9,581 at 86.3% on time.
Measured against the airport rather than the country, Delta Air Lines runs 10 points ahead of the 76.3% weighted average across all carriers at SAN. That is the comparison worth making: every operator here works the same runways, the same airspace and the same weather.
Key figures
On time
86.3%
9,448 completed departures
Avg delay
79 min
Across delayed flights only
Cancelled
1.17%
At SAN, this carrier only
Rank here
#1
Of 8 carriers clearing the floor at SAN
These figures cover 9,581 flights between September 2025 and August 2026. The median arrival is 9 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.
Against the competition
Every carrier at SAN, ranked
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 86.3% of the time; Southwest Airlines manages 70.6%. Sample sizes sit next to every figure, because a two-point gap across 39,067 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines (this page) | 9,581 | 86.3% | 79 min | 1.17% | A |
| American Airlines | 9,387 | 80.6% | 103 min | 1.64% | B |
| United Airlines | 10,655 | 79.7% | 69 min | 0.71% | B+ |
| Alaska Airlines | 13,373 | 79.0% | 57 min | 1.35% | B |
| JetBlue Airways | 1,643 | 78.8% | 97 min | 3.16% | B− |
| SkyWest Airlines | 14,921 | 77.8% | 58 min | 2.01% | B |
| Frontier Airlines | 2,105 | 71.5% | 81 min | 1.95% | C |
| Southwest Airlines | 39,067 | 70.6% | 51 min | 0.92% | C+ |
JetBlue Airways cancels 3.2% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Route by route
Where Delta Air Lines flies from SAN
Delta Air Lines operates 7 routes out of SAN with enough volume to report. Route records inside one carrier at one airport still spread widely, because a short shuttle and a transcontinental have very different exposure to a late inbound.
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SAN to ATL · Atlanta | 2,172 | 86.1% | 76 min | 0.69% | A+ |
| SAN to SLC · Salt Lake City | 1,739 | 88.1% | 71 min | 0.92% | A+ |
| SAN to SEA · Seattle | 1,710 | 86.6% | 77 min | 1.11% | A |
| SAN to MSP · Minneapolis | 1,300 | 89.1% | 83 min | 0.85% | A+ |
| SAN to DTW · Detroit | 1,250 | 86.1% | 52 min | 0.80% | A+ |
| SAN to JFK · New York | 1,046 | 82.8% | 111 min | 3.35% | B− |
| SAN to BOS · Bostonthin sample | 364 | 78.2% | 91 min | 1.65% | B |
Flight by flight
Delta Air Lines flight numbers from SAN
11 Delta Air Lines flight numbers leaving SAN flew their main route often enough to have a record of their own. Grouped by destination.
Departure window
Best time of day for this operation
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 9,581 flights.
- 5am–8am2,251 flights91.3%
- 8am–11am877 flights88.0%
- 11am–2pm2,585 flights84.3%
- 2pm–5pm1,288 flights84.1%
- 5pm–8pm1,070 flights83.7%
- 8pm–5am1,510 flights85.1%
Scale runs 75% to 95%.
The early departures do better, though not dramatically: 91.3% on time for the 5am–8am window against 83.7% for 5pm–8pm. Worth taking if the schedule allows, not worth an extra connection. The 11am–2pm window is the busiest, with 2,585 flights scheduled in it.
Across the year
Seasonal pattern
August is the worst month at 80.5% on time, 11 points below April, the best at 91.1%. 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. October was the busiest month here, with 851 flights.
Delay causes
What holds this operation up
- 41%Carrier
- 36%Late-arriving aircraft
- 18%National Airspace System
- 4%Extreme weather
- 0%Security
36% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 102,000 reported delay minutes here, that single category outweighs weather by 10 to one. The split is drawn from 101,746 reported delay minutes.
Cancellations sit at 1.17% against a national 1.89%, which is ordinary. Diversions add another 0.22%.
Badly late arrivals are rare here: only 4.3% land an hour or more behind schedule, against 8.3% 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.
The sample behind these figures is 9,581 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.
Put together: take the 5am–8am departure, avoid August if the dates are flexible, and if two carriers are within a few dollars of each other, Delta is the one with the record behind it. None of that guarantees an on-time arrival; it moves the odds by 16 points, which is the most any booking decision can do. 9,448 completed flights over 12 months sit behind that.
Common questions
Delta Air Lines at SAN
How often is Delta Air Lines at SAN delayed?
About one flight in seven arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 13.7% of the 9,581 flights in this analysis, against 22.7% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on Delta Air Lines at SAN?
Delta Air Lines leads at 86.3% on time across 9,581 flights. Southwest Airlines is at the other end on 70.6%, a gap of 16 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 Delta Air Lines at SAN?
The 5am–8am departure window is the strongest at 91.3% on time. The 5pm–8pm window is the weakest at 83.7%, 8 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 August delays on Delta Air Lines at SAN?
August is the weakest month at 80.5% on time, compared with 91.1% in April. Across the year that is 11 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
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.