Route reliability record
SEA→BNA
Seattle to Nashville
- Flights
- 1,481
- Period
- September 2025 to August 2026
- Distance
- 1,978 mi
- Carriers
- 3
This route lands a B+, 3 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 50 minutes on average. That rests on 1,481 SEA to BNA flights, of which Delta Air Lines flew 516 at 83.0% on time.
Best time to fly SEA to BNA: a 8am–11am departure, ideally on a Saturday. Flights in that window arrived on time 84.1% of the time and Saturday flights 85.6%, against 80.6% for the route overall.
The US average over the same twelve months is 77.3%, 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
80.6%
Arrivals under 15 minutes late, of 1,467 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
0.88%
National rate is 1.89%
Best carrier
Delta
83.0% on time across 516 flights
These figures cover 1,481 flights between September 2025 and August 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.
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Carrier by carrier
Which airline is most reliable on SEA to BNA
The two carriers here are closely matched: about a point separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 516 | 83.0% | 61 min | 0.97% | B+ |
| Alaska Airlines | 845 | 82.1% | 44 min | 0.95% | B+ |
| Southwest Airlinesthin sample | 120 | 60.0% | 39 min | 0.00% | D+ |
No carrier stands out. Delta tops the table at 83.0%, about a point clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
Flights on SEA to BNA
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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Best ways to make this trip
The most reliable ways to fly Seattle to Nashville
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. SEA → BNASeattle to Nashville | Delta Air Lines | 82.2% | 83.0% | 0.97% | 8am–11am, Thu | DL 815 17:35 |
| 2. SEA → BNASeattle to Nashville | Alaska Airlines | 81.3% | 82.1% | 0.95% | 8am–11am, Wed | AS 522 09:00 |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
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 26 points, against about a point between the best and worst carrier.
- 5am–8am—
- 8am–11am520 flights84.1%
- 11am–2pm31 flights58.1%
- 2pm–5pm14 flights—
- 5pm–8pm620 flights80.9%
- 8pm–5am296 flights75.1%
Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 58.1% on time against 84.1% for 8am–11am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 5pm–8pm window is the busiest, with 620 flights scheduled in it.
Explore
Filter SEA to BNA 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 SEA to BNA, the best departure window is 8am–11am at 84.1% on time and the worst is 11am–2pm at 58.1%, a wide gap of 26.0 points. All US flights leaving 8am–11am ran 83.9%.
- 5–8am—
- 8–11am84.1%
- 11am–2pm58.1%
- 2–5pm—
- 5–8pm80.9%
- 8pm–5am75.1%
best all US flightsScale 50% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 24 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.
July is the worst month at 68.3% on time, 24 points below April, the best at 92.4%. 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. July was the busiest month here, with 185 flights.
Across the week, Saturday is the strongest day at 85.6% on time and Friday the weakest at 77.0%, a spread of 9 points.
Delay causes
Why this route gets delayed
Carrier accounts for 44% of the 14,000 delay minutes carriers reported here, and the remaining four split what is left.
- 44%Carrier
- 33%Late-arriving aircraft
- 20%National Airspace System
- 3%Extreme weather
The largest share of delay minutes, 44%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 6,086 of the 14,000 delay minutes reported here. The split is drawn from 13,790 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 84.1% on time here.
Cancellations are rare at 0.88%, 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
Badly late arrivals are rare here: only 4.5% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
At 1,978 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 72.4% on time across 1,481 flights, 8 points below 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 8 points of difference.
The sample behind these figures is 1,481 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 BNA 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. April runs 92.4% on time and July 68.3%, a swing of 24 points. If the dates move at all, move them out of July before you think about anything else. 1,467 completed flights over 12 months sit behind that.
Common questions
SEA to BNA questions
How often is SEA 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 19.4% of the 1,481 flights in this analysis, against 22.7% nationally. Delayed flights are late by roughly 50 minutes on average.
Which airline is most reliable on SEA to BNA?
Delta Air Lines leads at 83.0% on time across 516 flights. Alaska Airlines is at the other end on 82.1%, a gap of about a point. 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 SEA to BNA?
The 8am–11am departure window is the strongest at 84.1% on time. The 11am–2pm window is the weakest at 58.1%, 26 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 SEA to BNA?
July is the weakest month at 68.3% on time, compared with 92.4% in April. Across the year that is 24 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 SEA — the return legseparate record
- Seattle-Tacoma International (SEA) delay statistics
- Nashville International (BNA) delay statistics
- Delta Air Lines on SEA to BNA83.0%
- Alaska Airlines on SEA to BNA82.1%
- Southwest Airlines on SEA to BNA60.0%
- SEA to LAX, a related route82.0%
- ORD to BNA, a related route69.2%
- SEA to PHX, a related route78.2%
- Delta Air Lines on-time record83.0%
- Alaska Airlines on-time record82.1%
- Southwest Airlines on-time record60.0%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. SEA to BNA and BNA to SEA 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.