Route reliability record
BNA→SFO
Nashville to San Francisco
- Flights
- 1,174
- Period
- September 2025 to August 2026
- Distance
- 1,969 mi
- Carriers
- 2
This route draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about an hour behind schedule. Build slack into anything you connect to. That rests on 1,174 BNA to SFO flights, with a median arrival 2 minutes late.
Best time to fly BNA to SFO: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 87.1% of the time and Tuesday flights 78.6%, against 67.9% for the route overall.
The national on-time rate over the same period is 77.3%, so this route runs 9 points behind the country as a whole. Across a thousand flights that is about 94 extra late arrivals.
Key figures
On time
67.9%
Arrivals under 15 minutes late, of 1,161 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
0.68%
National rate is 1.89%
Best carrier
United
74.6% on time across 862 flights
These figures cover 1,174 flights between September 2025 and August 2026. Beyond the headline rate, 10.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on BNA to SFO
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 | 862 | 74.6% | 58 min | 0.70% | C+ |
| Southwest Airlinesthin sample | 312 | 49.2% | 58 min | 0.64% | F+ |
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Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 34 points, against half a point between the best and worst carrier.
- 5am–8am277 flights87.1%
- 8am–11am201 flights78.9%
- 11am–2pm151 flights70.5%
- 2pm–5pm178 flights54.8%
- 5pm–8pm366 flights53.0%
- 8pm–5am1 flights—
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 53.0% on time, against 87.1% for the 5am–8am 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 5pm–8pm window is the busiest, with 366 flights scheduled in it.
Explore
Filter BNA to SFO by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On BNA to SFO, the best departure window is 5am–8am at 87.1% on time and the worst is 5pm–8pm at 53.0%, a wide gap of 34.1 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am87.1%
- 8–11am78.9%
- 11am–2pm70.5%
- 2–5pm54.8%
- 5–8pm53.0%
- 8pm–5am—
best all US flightsScale 45% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 40 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
June is the worst month at 46.7% on time, 40 points below September, the best at 86.8%. 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 114 flights.
Across the week, Tuesday is the strongest day at 78.6% on time and Sunday the weakest at 63.5%, a spread of 15 points.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 22,000 reported delay minutes.
- 40%National Airspace System
- 29%Carrier
- 29%Late-arriving aircraft
- 3%Extreme weather
40% 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 8,594 minutes out of 22,000, against a national NAS share of 21%. The split is drawn from 21,674 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 87.1% on time here.
Cancellations are rare at 0.68%, below the national 1.89% 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 actually costs
10.1% 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 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 72.0% on time across 1,174 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.
The sample behind these figures is 1,174 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.
Work out the risk of missing a connection in SFO after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 86.8% on time and June 46.7%, a swing of 40 points. If the dates move at all, move them out of June before you think about anything else. 1,161 completed flights over 12 months sit behind that.
Common questions
BNA to SFO questions
How often is BNA to SFO delayed?
About one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 32.1% of the 1,174 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
How reliable is BNA to SFO compared with the rest of the country?
67.9% of flights arrive on time here against a national 77.3%, a difference of 9 points against it. That is worth a C+ on this site's grading scale.
What time of day has the fewest delays on BNA to SFO?
The 5am–8am departure window is the strongest at 87.1% on time. The 5pm–8pm window is the weakest at 53.0%, 34 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 June delays on BNA to SFO?
June is the weakest month at 46.7% on time, compared with 86.8% in September. Across the year that is 40 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
- SFO to BNA — the return legseparate record
- Nashville International (BNA) delay statistics
- San Francisco International (SFO) delay statistics
- United Airlines on BNA to SFO74.6%
- Southwest Airlines on BNA to SFO49.2%
- BNA to ORD, a related route70.9%
- LAX to SFO, a related route60.1%
- BNA to DCA, a related route71.3%
- United Airlines on-time record74.6%
- Southwest Airlines on-time record49.2%
- The best time of day to fly, according to 7.05 million flight records
- How often a connection fails at the major US hubs
Direction matters. BNA to SFO and SFO to BNA are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.