Carrier route record

ASBNA→SEA

Alaska Airlines · Nashville to Seattle

Flights: 843
Period: July 2025 to June 2026
Share of route: 57%
Carriers: 3

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Alaska Airlines.

Alaska on BNA to SEA sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 843 flights, with a median arrival 1 minute late.

The national on-time rate over the same period is 77.6%, so Alaska on BNA to SEA runs 7 points behind the country as a whole. Across a thousand flights that is about 73 extra late arrivals.

On time

70.3%

Arrivals under 15 minutes late, of 829 completed flights

Avg delay

49 min

Across delayed arrivals only, not all flights

Cancelled

1.42%

National rate is 1.81%

Whole route

72.7%

Every carrier on BNA to SEA, 1,479 flights

These figures cover 843 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.

Carrier by carrier

Alaska against every carrier on BNA to SEA

Alaska flew 843 of the 1,479 flights on BNA to SEA, most of the route. Its 70.3% on time is 2 points worse than the route as a whole, which runs 72.7%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Delta at 83.4% to Southwest at 44.7%. 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.

On-time performance by carrier on BNA to SEA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	511	83.4%	66 min	0.78%	B+
Alaska Airlines (this page)	843	70.3%	49 min	1.42%	C
Southwest Airlinesthin sample	125	44.7%	52 min	0.80%	F+

Departure window

When Alaska runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 31 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–8am339 flights72.6%
8am–11am166 flights85.4%
11am–2pm—
2pm–5pm111 flights74.1%
5pm–8pm227 flights54.2%
8pm–5am—

Scale runs 45% to 90%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 54.2% on time, against 85.4% for the 8am–11am 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 339 flights scheduled in it.

Across the year

Alaska on BNA to SEA through the year

Darker means more delays. Figures are on-time percentages.February best, December worst

December is the weak month at 44.8% on time, against 83.3% in February. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 92 flights.

Across the week, Wednesday is the strongest day at 76.1% on time and Friday the weakest at 64.2%. 12 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Alaska runs late on this route

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 12,000 reported delay minutes.

National Airspace System
33%
Carrier
31%
Late-arriving aircraft
31%
Extreme weather
4%
Security
0%

33% 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 3,952 minutes out of 12,000, against a national NAS share of 21%. The split is drawn from 11,960 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 85.4% on time here.

Cancellations sit at 1.42% against a national 1.81%, which is ordinary. Diversions add another 0.24%.

Connections and stage length

What a delay here costs

6.5% 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 roughly 50 minutes, which a normal layover absorbs.

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 77.0% on time across 843 flights, 7 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 7 points of difference.

One caution: this is a thin sample. 843 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 Alaska on BNA to SEA

Put together: treat all of this as provisional. 843 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 70.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 829 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures