Carrier performance at one airport
UA→SAN
United Airlines at San Diego International
- Departures
- 10,504
- Period
- July 2025 to June 2026
- Routes
- 7
- Rank here
- #4 of 10
United Airlines at San Diego lands a B+, 4 points better than the national rate of 77.6%. About one flight in five arrive 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 10,504 flights, of which Delta Air Lines flew 9,577 at 86.8% on time.
Measured against the airport rather than the country, United Airlines runs 3 points ahead of the 78.0% 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
81.3%
10,381 completed departures
Avg delay
69 min
Across delayed flights only
Cancelled
0.75%
At SAN, this carrier only
Rank here
#4
Of 10 carriers clearing the floor at SAN
These figures cover 11,000 flights between July 2025 and June 2026. The median arrival is 8 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 86.8% of the time; Hawaiian Airlines manages 60.8%. Sample sizes sit next to every figure, because a two-point gap across 487 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 9,577 | 86.8% | 76 min | 1.13% | A |
| Spirit Airlines | 400 | 82.2% | 65 min | 1.50% | B |
| JetBlue Airways | 1,646 | 81.5% | 106 min | 2.25% | B |
| United Airlines (this page) | 10,504 | 81.3% | 69 min | 0.75% | B+ |
| American Airlines | 9,358 | 80.6% | 102 min | 1.86% | B |
| SkyWest Airlines | 14,952 | 79.8% | 58 min | 1.77% | B |
| Alaska Airlines | 12,721 | 78.8% | 57 min | 1.46% | B |
| Southwest Airlines | 37,660 | 73.5% | 51 min | 0.91% | C+ |
| Frontier Airlines | 2,265 | 72.3% | 82 min | 2.03% | C |
| Hawaiian Airlines | 487 | 60.8% | 78 min | 1.64% | D |
The spread between Delta and Hawaiian is 26 points, wide enough that it should decide the booking. On a hundred trips that is 26 more arrivals inside the on-time window.
Route by route
Where United Airlines flies from SAN
United Airlines 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 SFO · San Francisco | 2,598 | 70.6% | 60 min | 0.65% | C+ |
| SAN to DEN · Denver | 2,081 | 85.4% | 65 min | 0.77% | A+ |
| SAN to IAH · Houston | 1,693 | 84.5% | 72 min | 0.53% | B+ |
| SAN to ORD · Chicago | 1,672 | 82.0% | 76 min | 0.54% | B+ |
| SAN to EWR · Newark | 1,233 | 82.9% | 82 min | 1.87% | B |
| SAN to IAD · Washington | 1,040 | 89.5% | 87 min | 0.48% | A+ |
| SAN to LAX · Los Angelesthin sample | 187 | 92.0% | 63 min | 0.00% | A+ |
Departure window
Best time of day for this operation
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 12 points, against 26 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am2,006 flights86.6%
- 8am–11am1,926 flights82.9%
- 11am–2pm2,224 flights80.4%
- 2pm–5pm1,813 flights74.6%
- 5pm–8pm1,184 flights75.1%
- 8pm–5am1,351 flights86.9%
Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.
The overnight block holds up unusually well at 86.9% on time across 1,351 flights. Red-eyes fly into empty airspace and empty gates, and they are the first rotation of the aircraft's day rather than the last. The 11am–2pm window is the busiest, with 2,224 flights scheduled in it.
Across the year
Seasonal pattern
July is the worst month at 75.5% on time, 12 points below February, the best at 87.3%. 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. May was the busiest month here, with 933 flights.
Delay causes
What holds this operation up
- 42%National Airspace System
- 33%Late-arriving aircraft
- 20%Carrier
- 5%Extreme weather
42% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 57,000 minutes out of 134,000, against a national NAS share of 21%. The split is drawn from 133,664 reported delay minutes.
Cancellations are rare at 0.75%, 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.
6.3% 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 are the a little over an hour kind, which a normal layover absorbs.
The sample behind these figures is 10,504 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: United's SAN operation record is 81.3% on time with 0.75% cancelled, worth a B+. The largest single lever is the 8pm–5am departure window, and the numbers below the table are where the reasoning behind that lives. 10,381 completed flights over 12 months sit behind that.
Common questions
United Airlines at SAN
How often is United Airlines at SAN delayed?
About one flight in five arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 18.7% of the 10,504 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on United Airlines at SAN?
Delta Air Lines leads at 86.8% on time across 9,577 flights. Hawaiian Airlines is at the other end on 60.8%, a gap of 26 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 United Airlines at SAN?
The 8pm–5am departure window is the strongest at 86.9% on time. The 2pm–5pm window is the weakest at 74.6%, 12 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 July delays on United Airlines at SAN?
July is the weakest month at 75.5% on time, compared with 87.3% in February. Across the year that is 12 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, July 2025 to June 2026. Updated monthly. How this data is collected.