Carrier route record
UABNA→SFO
United Airlines · Nashville to San Francisco
- Flights
- 851
- Period
- July 2025 to June 2026
- Share of route
- 73%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on BNA to SFO lands a B+, about a point worse than the national rate of 77.6%. About one flight in four arrives 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 851 flights, with a median arrival 2 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate United on BNA to SFO from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
76.3%
Arrivals under 15 minutes late, of 840 completed flights
Avg delay
60 min
Across delayed arrivals only, not all flights
Cancelled
0.82%
National rate is 1.81%
Whole route
70.6%
Every carrier on BNA to SFO, 1,162 flights
These figures cover 851 flights between July 2025 and June 2026. The median arrival is 2 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
United against every carrier on BNA to SFO
United flew 851 of the 1,162 flights on BNA to SFO, most of the route. Its 76.3% on time is 6 points better than the route as a whole, which runs 70.6%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 76.3% to Southwest at 55.2%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 Airlines (this page) | 851 | 76.3% | 60 min | 0.82% | B+ |
| Southwest Airlinesthin sample | 311 | 55.2% | 55 min | 0.64% | D+ |
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 33 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am298 flights86.9%
- 8am–11am169 flights79.2%
- 11am–2pm30 flights96.7%
- 2pm–5pm92 flights67.0%
- 5pm–8pm262 flights63.5%
- 8pm–5am—
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 63.5% on time, against 96.7% for the 11am–2pm slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 298 flights scheduled in it.
Across the year
United on BNA to SFO through the year
September is the best month on the calendar at 93.4% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. March was the busiest month here, with 84 flights.
Across the week, Saturday is the strongest day at 85.3% on time and Sunday the weakest at 69.6%. 16 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
One category carries most of the weight here. National Airspace System accounts for 47% of the 12,000 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.
- 47%National Airspace System
- 28%Carrier
- 20%Late-arriving aircraft
- 4%Extreme weather
47% 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 5,682 minutes out of 12,000, against a national NAS share of 21%. The split is drawn from 12,013 reported delay minutes.
Cancellations are rare at 0.82%, 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.
Connections and stage length
What a delay here costs
7.5% 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 last about an hour, which a normal layover absorbs.
At 1,969 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 79.9% on time across 851 flights, 4 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 4 points of difference.
One caution: this is a thin sample. 851 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 BNA to SFO
Put together: treat all of this as provisional. 851 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 76.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 840 completed flights over 12 months sit behind that.
Related
Where to go next
- BNA to SFO, every carrier
- United on SFO to BNA, the return leg
- Southwest Airlines on BNA to SFO55.2%
- United Airlines network-wide record
- Nashville International (BNA) delay statistics
- San Francisco International (SFO) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.