Carrier route record

ASSEA→TPA

Alaska Airlines · Seattle to Tampa

Flights: 613
Period: July 2025 to June 2026
Share of route: 63%
Carriers: 2

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

Alaska on SEA to TPA 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 roughly 45 minutes on average. That is a workable record, not a spotless one. That rests on 613 flights, with a median arrival 8 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Alaska on SEA to TPA from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

79.9%

Arrivals under 15 minutes late, of 603 completed flights

Avg delay

43 min

Across delayed arrivals only, not all flights

Cancelled

0.65%

National rate is 1.81%

Whole route

78.6%

Every carrier on SEA to TPA, 976 flights

These figures cover 613 flights between July 2025 and June 2026. The median arrival is 8 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

Alaska against every carrier on SEA to TPA

Alaska flew 613 of the 976 flights on SEA to TPA, most of the route. Its 79.9% on time is about level with the route as a whole at 78.6%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Alaska at 79.9% to Delta at 76.3%. 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.

On-time performance by carrier on SEA to TPA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Alaska Airlines (this page)	613	79.9%	43 min	0.65%	B+
Delta Air Linesthin sample	363	76.3%	55 min	0.55%	B+

Flight by flight

Alaska flight numbers on SEA to TPA

AS 32609:1183.0% · 344 flights

Departure window

When Alaska runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 613 flights.

5am–8am—
8am–11am365 flights82.6%
11am–2pm—
2pm–5pm—
5pm–8pm—
8pm–5am248 flights76.1%

Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.

The early departures do better, though not dramatically: 82.6% on time for the 8am–11am window against 76.1% for 8pm–5am. Worth taking if the schedule allows, not worth an extra connection. The 8am–11am window is the busiest, with 365 flights scheduled in it.

Across the year

Alaska on SEA to TPA through the year

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

July is the worst month at 58.3% on time, 40 points below February, the best at 97.8%. 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. July was the busiest month here, with 62 flights.

Across the week, Wednesday is the strongest day at 85.0% on time and Monday the weakest at 75.8%. 9 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Alaska runs late on this route

One category carries most of the weight here. Carrier accounts for 48% of the 5,205 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.

Carrier
48%
Late-arriving aircraft
31%
National Airspace System
20%
Extreme weather
1%

The largest share of delay minutes, 48%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 2,515 of the 5,205 delay minutes reported here. The split is drawn from 5,205 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 82.6% on time here.

Cancellations are rare at 0.65%, 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 costs

Badly late arrivals are rare here: only 3.6% land an hour or more behind schedule, against 8.1% 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 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 68.0% on time across 613 flights, 12 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 12 points of difference.

One caution: this is a thin sample. 613 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 SEA to TPA

Put together: treat all of this as provisional. 613 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 79.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 603 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