Carrier route record
ASTPA→SEA
Alaska Airlines · Tampa to Seattle
- Flights
- 612
- Period
- September 2025 to August 2026
- Share of route
- 63%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on TPA 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, 9 points worse than the national rate of 77.3%. The late ones land roughly 50 minutes behind schedule. That rests on 612 flights, with a median arrival 4 minutes late.
The national on-time rate over the same period is 77.3%, so Alaska on TPA to SEA runs 9 points behind the country as a whole. Across a thousand flights that is about 90 extra late arrivals.
Key figures
On time
68.3%
Arrivals under 15 minutes late, of 602 completed flights
Avg delay
52 min
Across delayed arrivals only, not all flights
Cancelled
0.98%
National rate is 1.89%
Whole route
74.2%
Every carrier on TPA to SEA, 975 flights
These figures cover 612 flights between September 2025 and August 2026. Beyond the headline rate, 8.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Alaska against every carrier on TPA to SEA
Alaska flew 612 of the 975 flights on TPA to SEA, most of the route. Its 68.3% on time is 6 points worse than the route as a whole, which runs 74.2%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Delta at 84.3% to Alaska at 68.3%. 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 |
|---|---|---|---|---|---|
| Delta Air Linesthin sample | 363 | 84.3% | 41 min | 0.83% | B+ |
| Alaska Airlines (this page) | 612 | 68.3% | 52 min | 0.98% | C+ |
Flight by flight
Alaska flight numbers on TPA to SEA
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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 10 points, against half a point between the best and worst carrier.
- 5am–8am310 flights73.2%
- 8am–11am—
- 11am–2pm—
- 2pm–5pm—
- 5pm–8pm302 flights63.2%
- 8pm–5am—
Scale runs 55% to 80%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 63.2% on time, against 73.2% 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 310 flights scheduled in it.
Across the year
Alaska on TPA to SEA through the year
December is the weak month at 51.9% on time, against 84.2% in November. 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. May was the busiest month here, with 62 flights.
Across the week, Tuesday is the strongest day at 76.8% on time and Friday the weakest at 59.6%, a spread of 17 points.
Arrival by arrival
How late Alaska on TPA to SEA runs when it is late
The 191 late arrivals split 83 under half an hour, 60 between 30 and 60 minutes, and 48 an hour or more.
- 15+ min early107 flights17.8%
- Within 15 min304 flights50.5%
- 15–29 min late83 flights13.8%
- 30–59 min late60 flights10.0%
- 1–2 hours late34 flights5.6%
- 2+ hours late14 flights2.3%
Scale runs 0% to 100%.
Share of 602 completed flights by arrival against schedule.
42 of 163 late departures made up the time and arrived on time, 26% of them. In the other direction, 70 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at SEA.
The worst days
Worst days for Alaska on TPA to SEA
The latest arrival of the period was on 12 April 2026, 6 hours 9 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 12 April 2026 | 6 hours 9 minutes | Late-arriving aircraft |
| 4 October 2025 | 4 hours 52 minutes | Late-arriving aircraft |
| 16 April 2026 | 4 hours 26 minutes | Late-arriving aircraft |
| 8 May 2026 | 4 hours 13 minutes | Carrier |
| 5 July 2026 | 3 hours 24 minutes | Carrier |
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 9,839 reported delay minutes.
- 40%Late-arriving aircraft
- 30%Carrier
- 26%National Airspace System
- 4%Extreme weather
- 0%Security
40% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 9,839 reported delay minutes here, that single category outweighs weather by 11 to one. The split is drawn from 9,839 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 73.2% on time here.
Cancellations sit at 0.98% against a national 1.89%, which is ordinary. Diversions add another 0.65%.
Connections and stage length
What a delay here costs
8.0% of arrivals land an hour or more late, close to the national 8.3%, so 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 2,520 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 81.3% on time across 612 flights, 13 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 13 points of difference.
One caution: this is a thin sample. 612 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 TPA to SEA
Put together: treat all of this as provisional. 612 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 68.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 602 completed flights over 12 months sit behind that.
Related
Where to go next
- TPA to SEA, every carrier
- Alaska on SEA to TPA, the return leg
- Delta Air Lines on TPA to SEA84.3%
- Alaska Airlines network-wide record
- Tampa International (TPA) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
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.