Carrier route record
UASBP→SFO
United Airlines · San Luis Obispo to San Francisco
- Flights
- 303
- Period
- September 2025 to August 2026
- Share of route
- 27%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on SBP to SFO earns an F+, which is as low as this site's scale goes for a reason. Only 51.3% of flights arrive inside the 15-minute window, 26 points worse than the national rate of 77.3%. Late arrivals average a little over an hour. Treat any tight connection here as a coin flip. That rests on 303 flights, with a median arrival 13 minutes late.
The national on-time rate over the same period is 77.3%, so United on SBP to SFO runs 26 points behind the country as a whole. Across a thousand flights that is about 260 extra late arrivals.
Key figures
On time
51.3%
Arrivals under 15 minutes late, of 300 completed flights
Avg delay
78 min
Across delayed arrivals only, not all flights
Cancelled
0.99%
National rate is 1.89%
Whole route
56.4%
Every carrier on SBP to SFO, 1,139 flights
These figures cover 303 flights between September 2025 and August 2026. Beyond the headline rate, 19.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
United against every carrier on SBP to SFO
United flew 303 of the 1,139 flights on SBP to SFO, about 27% of it. Its 51.3% on time is 5 points worse than the route as a whole, which runs 56.4%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 58.2% to United at 51.3%.
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 |
|---|---|---|---|---|---|
| SkyWest Airlines | 836 | 58.2% | 70 min | 1.32% | D |
| United Airlines (this page)thin sample | 303 | 51.3% | 78 min | 0.99% | F+ |
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 55 points, against half a point between the best and worst carrier.
- 5am–8am174 flights75.4%
- 8am–11am21 flights—
- 11am–2pm—
- 2pm–5pm102 flights20.6%
- 5pm–8pm—
- 8pm–5am6 flights—
Scale runs 10% to 80%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 75.4% of the time, against 20.6% for the afternoon window. That is 55 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 174 flights scheduled in it.
Across the year
United on SBP to SFO through the year
- Jan–Mar 202642 flights85.4%
- Apr–Jun 2026138 flights53.3%
- Jul–Sep 2026123 flights37.7%
Scale runs 30% to 90%.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 51.3% on time across 303 flights.
United on SBP to SFO did not run the same all year. Its best quarter was Jan–Mar 2026 at 85.4% on time and its weakest Jul–Sep 2026 at 37.7%, a swing of 48 points on roughly 101 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
Across the week, Monday is the strongest day at 58.1% on time and Wednesday the weakest at 37.5%, a spread of 21 points.
Arrival by arrival
How late United on SBP to SFO runs when it is late
The 146 late arrivals split 42 under half an hour, 47 between 30 and 60 minutes, and 57 an hour or more.
- 15+ min early17 flights5.7%
- Within 15 min137 flights45.7%
- 15–29 min late42 flights14.0%
- 30–59 min late47 flights15.7%
- 1–2 hours late38 flights12.7%
- 2+ hours late19 flights6.3%
Scale runs 0% to 100%.
Share of 300 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 111 departures that left 15 minutes late or more, only 4 made it up before arrival. In the other direction, 39 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 SFO.
The worst days
Worst days for United on SBP to SFO
The latest arrival of the period was on 16 May 2026, 11 hours 30 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 16 May 2026 | 11 hours 30 minutes | Carrier |
| 21 March 2026 | 11 hours 3 minutes | Carrier |
| 6 August 2026 | 8 hours 10 minutes | Carrier |
| 4 June 2026 | 7 hours 54 minutes | Late-arriving aircraft |
| 21 April 2026 | 6 hours 52 minutes | Carrier |
Delay causes
Why United runs late on this route
National Airspace System accounts for 51% of the 11,000 delay minutes carriers reported here, and the remaining four split what is left.
- 51%National Airspace System
- 40%Carrier
- 8%Late-arriving aircraft
- 1%Extreme weather
The largest share of delay minutes, 40%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 4,594 of the 11,000 delay minutes reported here. The split is drawn from 11,400 reported delay minutes.
51% 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 5,791 minutes out of 11,000, against a national NAS share of 21%.
Cancellations sit at 0.99% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
19.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 191 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 69.4% on time across 304 flights, 18 points above 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 18 points of difference.
One caution: this is a thin sample. 303 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking United on SBP to SFO
Put together: treat all of this as provisional. 303 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 51.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 300 completed flights over 12 months sit behind that.
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.