Route reliability record
SAT→BNA
San Antonio to Nashville
- Flights
- 950
- Period
- July 2025 to June 2026
- Distance
- 822 mi
- Carriers
- 2
This route lands a B+, 2 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 55 minutes on average. That is a workable record, not a spotless one. That rests on 950 SAT to BNA flights, with a median arrival 3 minutes early.
Best time to fly SAT to BNA: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 95.3% of the time and Tuesday flights 86.9%, against 79.3% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
79.3%
Arrivals under 15 minutes late, of 943 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
0.53%
National rate is 1.81%
Best carrier
Southwest
79.8% on time across 938 flights
These figures cover 950 flights between July 2025 and June 2026. The median arrival is 3 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
Which airline is most reliable on SAT to BNA
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 |
|---|---|---|---|---|---|
| Southwest Airlines | 938 | 79.8% | 52 min | 0.53% | B+ |
| Spirit Airlinesthin sample | 12 | 41.7% | 118 min | 0.00% | F+ |
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 40 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–8am363 flights95.3%
- 8am–11am40 flights95.0%
- 11am–2pm165 flights73.3%
- 2pm–5pm269 flights69.2%
- 5pm–8pm113 flights55.4%
- 8pm–5am—
Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 55.4% on time, against 95.3% 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 5am–8am window is the busiest, with 363 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 26 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 66.3% on time, 26 points below September, the best at 91.8%. 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 88 flights.
Across the week, Tuesday is the strongest day at 86.9% on time and Thursday the weakest at 71.6%. 15 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 45% of the 11,000 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.
- 45%Late-arriving aircraft
- 30%Carrier
- 24%National Airspace System
- 2%Extreme weather
- 0%Security
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 11,000 reported delay minutes here, that single category outweighs weather by 27 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. The split is drawn from 10,622 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 95.3% on time here.
Cancellations are rare at 0.53%, 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 actually costs
5.8% 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 55 minutes, which a normal layover absorbs.
The 822 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg runs 79.1% on time across 950 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 950 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.
Work out the risk of missing a connection in BNA after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 950 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 79.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 943 completed flights over 12 months sit behind that.
Common questions
SAT to BNA questions
How often is SAT to BNA delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 20.7% of the 950 flights in this analysis, against 22.4% nationally. Delayed flights are late by about 55 minutes on average.
How reliable is SAT to BNA compared with the rest of the country?
79.3% of flights arrive on time here against a national 77.6%, a difference of 2 points in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on SAT to BNA?
The 5am–8am departure window is the strongest at 95.3% on time. The 5pm–8pm window is the weakest at 55.4%, 40 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 SAT to BNA?
June is the weakest month at 66.3% on time, compared with 91.8% in September. Across the year that is 26 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
- BNA to SAT — the return legseparate record
- San Antonio International (SAT) delay statistics
- Nashville International (BNA) delay statistics
- SAT to DFW, a related route77.1%
- ORD to BNA, a related route68.6%
- SAT to DEN, a related route81.0%
- Southwest Airlines on-time record79.8%
- Spirit Airlines on-time record41.7%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. SAT to BNA and BNA to SAT 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.