Carrier performance at one airport
UA→SFO
United Airlines at San Francisco International
- Departures
- 59,976
- Period
- June 2025 to May 2026
- Routes
- 25
- Rank here
- #1 of 9
United Airlines at San Francisco lands a B+, 4 points better than the national rate of 77.4%. Roughly one flight in five arrive 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 59,976 flights, of which United Airlines flew 59,976 at 81.7% on time.
Measured against the airport rather than the country, United Airlines runs 3 points ahead of the 78.3% weighted average across all carriers at SFO. That is the comparison worth making: every operator here works the same runways, the same airspace and the same weather.
Key figures
On time
81.7%
59,464 completed departures
Avg delay
59 min
Across delayed flights only
Cancelled
0.56%
At SFO, this carrier only
Rank here
#1
Of 9 carriers clearing the floor at SFO
These figures cover 60,000 flights between June 2025 and May 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.
Against the competition
Every carrier at SFO, ranked
The choice of carrier is not cosmetic here. United Airlines arrives on time 81.7% of the time; Southwest Airlines manages 61.9%. Sample sizes sit next to every figure, because a two-point gap across 9,132 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines (this page) | 59,976 | 81.7% | 59 min | 0.56% | B+ |
| Delta Air Lines | 13,738 | 80.0% | 70 min | 1.21% | B |
| JetBlue Airways | 4,340 | 80.0% | 75 min | 1.57% | B |
| American Airlines | 11,739 | 78.5% | 101 min | 1.88% | B |
| SkyWest Airlines | 32,426 | 77.8% | 74 min | 1.19% | B |
| Alaska Airlines | 10,622 | 76.1% | 55 min | 1.13% | B |
| Hawaiian Airlines | 593 | 75.6% | 65 min | 1.85% | B |
| Frontier Airlines | 3,323 | 65.5% | 83 min | 1.93% | C |
| Southwest Airlines | 9,132 | 61.9% | 58 min | 0.79% | D+ |
The spread between United and Southwest is 20 points, wide enough that it should decide the booking. On a hundred trips that is 20 more arrivals inside the on-time window.
Route by route
Where United Airlines flies from SFO
United Airlines operates 25 routes out of SFO 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 |
|---|---|---|---|---|---|
| SFO to ORD · Chicago | 3,774 | 78.8% | 68 min | 1.01% | B |
| SFO to EWR · Newark | 3,750 | 74.1% | 82 min | 2.40% | C |
| SFO to IAH · Houston | 3,596 | 84.5% | 53 min | 0.36% | B+ |
| SFO to DEN · Denver | 3,364 | 82.1% | 59 min | 0.30% | B+ |
| SFO to LAX · Los Angeles | 3,255 | 79.6% | 49 min | 0.25% | B+ |
| SFO to LAS · Las Vegas | 2,733 | 80.9% | 54 min | 0.40% | B+ |
| SFO to IAD · Washington | 2,671 | 84.1% | 64 min | 0.75% | B+ |
| SFO to SAN · San Diego | 2,585 | 76.6% | 56 min | 0.46% | B+ |
| SFO to SEA · Seattle | 2,014 | 77.7% | 55 min | 0.30% | B+ |
| SFO to BOS · Boston | 1,815 | 78.7% | 74 min | 0.99% | B+ |
| SFO to HNL · Honolulu | 1,712 | 86.9% | 73 min | 0.29% | A+ |
| SFO to AUS · Austin | 1,644 | 83.9% | 51 min | 0.79% | B+ |
| SFO to PDX · Portland | 1,642 | 82.6% | 58 min | 0.18% | B+ |
| SFO to BUR · Burbank | 1,461 | 82.0% | 55 min | 0.14% | B+ |
| SFO to PHX · Phoenix | 1,452 | 81.6% | 59 min | 0.48% | B+ |
| SFO to OGG · Kahului | 1,225 | 90.2% | 39 min | 0.41% | A+ |
| SFO to MCO · Orlando | 1,041 | 86.6% | 55 min | 0.29% | A+ |
| SFO to ONT · Ontario | 1,037 | 81.0% | 57 min | 0.29% | B+ |
| SFO to SBA · Santa Barbara | 1,031 | 82.6% | 55 min | 0.87% | B+ |
| SFO to SNA · Santa Ana | 1,011 | 84.4% | 47 min | 0.49% | B+ |
| SFO to RDU · Raleigh | 902 | 90.4% | 59 min | 0.22% | A+ |
| SFO to RNO · Reno | 879 | 79.2% | 53 min | 0.46% | B+ |
| SFO to BNA · Nashville | 856 | 80.2% | 50 min | 0.70% | B+ |
| SFO to KOA · Kailua-Kona | 806 | 85.5% | 48 min | 0.37% | A+ |
| SFO to DFW · Dallas-Fort Worth | 804 | 79.2% | 54 min | 0.50% | B+ |
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 18 points, against 20 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am5,228 flights94.4%
- 8am–11am15,329 flights83.8%
- 11am–2pm9,947 flights77.4%
- 2pm–5pm9,315 flights76.2%
- 5pm–8pm7,026 flights82.9%
- 8pm–5am13,131 flights80.8%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 94.4% of the time, against 76.2% for the afternoon window. That is 18 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on.
Across the year
Seasonal pattern
July is the worst month at 75.7% on time, 10 points below March, the best at 85.4%. 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.
Delay causes
What holds this operation up
- 45%Late-arriving aircraft
- 29%Carrier
- 25%National Airspace System
- 1%Extreme weather
45% 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 638,000 reported delay minutes here, that single category outweighs weather by 45 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.
Cancellations are rare at 0.56%, below the national 1.80% 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.
5.6% of arrivals land an hour or more late, close to the national 8.2%. 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 about an hour kind, which a normal layover absorbs.
59,976 flights sit behind these numbers, which is a large enough sample that the headline rate is not moving on noise. Where a sub-group falls below 30 flights the site shows a dash instead of a percentage.
Put together: take the 5am–8am departure, avoid July if the dates are flexible, and if two carriers are within a few dollars of each other, United is the one with the record behind it. None of that guarantees an on-time arrival; it moves the odds by 20 points, which is the most any booking decision can do.
Common questions
United Airlines at SFO
How often is United Airlines at SFO delayed?
Roughly 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 18.3% of the 59,976 flights in this analysis, against 22.6% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on United Airlines at SFO?
United Airlines leads at 81.7% on time across 59,976 flights. Southwest Airlines is at the other end on 61.9%, a gap of 20 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 SFO?
The 5am–8am departure window is the strongest at 94.4% on time. The 2pm–5pm window is the weakest at 76.2%, 18 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 SFO?
July is the weakest month at 75.7% on time, compared with 85.4% in March. Across the year that is 10 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, June 2025 to May 2026. Updated monthly. How this data is collected.