Carrier route record
DLTPA→SEA
Delta Air Lines · Tampa to Seattle
- Flights
- 363
- Period
- July 2025 to June 2026
- Share of route
- 37%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on TPA to SEA earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 363 flights, with a median arrival 6 minutes early.
Set against the rest of the country, Delta's TPA to SEA record is 9 points better than the US average of 77.6%. That gap is worth roughly 90 fewer late arrivals for every thousand flights.
Key figures
On time
86.6%
Arrivals under 15 minutes late, of 359 completed flights
Avg delay
68 min
Across delayed arrivals only, not all flights
Cancelled
0.83%
National rate is 1.81%
Whole route
74.9%
Every carrier on TPA to SEA, 976 flights
These figures cover 363 flights between July 2025 and June 2026. The median arrival is 6 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
Delta against every carrier on TPA to SEA
Delta flew 363 of the 976 flights on TPA to SEA, about 37% of it. Its 86.6% on time is 12 points better than the route as a whole, which runs 74.9%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Delta at 86.6% to Alaska at 68.0%.
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 Lines (this page)thin sample | 363 | 86.6% | 68 min | 0.83% | A+ |
| Alaska Airlines | 613 | 68.0% | 50 min | 0.82% | C+ |
Flight by flight
Delta flight numbers on TPA to SEA
Departure window
When Delta 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 363 flights.
- 5am–8am84 flights90.2%
- 8am–11am279 flights85.6%
- 11am–2pm—
- 2pm–5pm—
- 5pm–8pm—
- 8pm–5am—
Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.
The early departures do better, though not dramatically: 90.2% on time for the 5am–8am window against 85.6% for 8am–11am. Worth taking if the schedule allows, not worth an extra connection. The 8am–11am window is the busiest, with 279 flights scheduled in it.
Across the year
Delta on TPA to SEA through the year
July is the worst month at 74.2% on time, 23 points below April, the best at 96.7%. 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. January was the busiest month here, with 31 flights.
Across the week, Sunday is the strongest day at 92.2% on time and Tuesday the weakest at 79.2%. 13 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Delta runs late on this route
One category carries most of the weight here. Carrier accounts for 62% of the 3,238 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.
- 62%Carrier
- 25%National Airspace System
- 14%Late-arriving aircraft
The largest share of delay minutes, 62%, 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 1,998 of the 3,238 delay minutes reported here. The split is drawn from 3,238 reported delay minutes.
Cancellations are rare at 0.83%, 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 3.9% 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 76.3% on time across 363 flights, 10 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 10 points of difference.
One caution: this is a thin sample. 363 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 Delta on TPA to SEA
Put together: treat all of this as provisional. 363 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 86.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 359 completed flights over 12 months sit behind that.
Related
Where to go next
- TPA to SEA, every carrier
- Delta on SEA to TPA, the return leg
- Alaska Airlines on TPA to SEA68.0%
- Delta Air Lines network-wide record
- Tampa International (TPA) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Worst months to fly in the US, ranked by the data
- How to read this site: grades, sample sizes, and honest caveats
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.