Carrier route record
DLTPA→SEA
Delta Air Lines · Tampa to Seattle
- Flights
- 363
- Period
- September 2025 to August 2026
- Share of route
- 37%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on TPA to SEA earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 40 minutes. 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 7 points better than the US average of 77.3%. That gap is worth roughly 70 fewer late arrivals for every thousand flights.
Key figures
On time
84.3%
Arrivals under 15 minutes late, of 357 completed flights
Avg delay
41 min
Across delayed arrivals only, not all flights
Cancelled
0.83%
National rate is 1.89%
Whole route
74.2%
Every carrier on TPA to SEA, 975 flights
These figures cover 363 flights between September 2025 and August 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.
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Carrier by carrier
Delta against every carrier on TPA to SEA
Delta flew 363 of the 975 flights on TPA to SEA, about 37% of it. Its 84.3% on time is 10 points better than the route as a whole, which runs 74.2%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Delta at 84.3% to Alaska at 68.3%.
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 | 84.3% | 41 min | 0.83% | B+ |
| Alaska Airlines | 612 | 68.3% | 52 min | 0.98% | C+ |
Flight by flight
Delta flight numbers on TPA to SEA
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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–8am146 flights81.7%
- 8am–11am217 flights86.0%
- 11am–2pm—
- 2pm–5pm—
- 5pm–8pm—
- 8pm–5am—
Scale runs 75% to 90%. Rows with fewer than 30 flights show a dash.
The early departures do better, though not dramatically: 86.0% on time for the 8am–11am window against 81.7% for 5am–8am. Worth taking if the schedule allows, not worth an extra connection. The 8am–11am window is the busiest, with 217 flights scheduled in it.
Across the year
Delta on TPA to SEA through the year
August is the worst month at 63.3% on time, 33 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 90.0% on time and Monday the weakest at 75.5%, a spread of 15 points.
Arrival by arrival
How late Delta on TPA to SEA runs when it is late
Delta on TPA to SEA often beats the schedule: 108 of 357 completed flights, 30%, arrived 15 minutes or more early. Most of the lateness is short. 34 of the 56 late arrivals were under half an hour behind, and 10 reached an hour or more.
- 15+ min early108 flights30.3%
- Within 15 min193 flights54.1%
- 15–29 min late34 flights9.5%
- 30–59 min late12 flights3.4%
- 1–2 hours late5 flights1.4%
- 2+ hours late5 flights1.4%
Scale runs 0% to 100%.
Share of 357 completed flights by arrival against schedule.
A late pushback is often recovered here: of 30 departures that left 15 minutes late or more, 9 still arrived on time. In the other direction, 35 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 Delta on TPA to SEA
The latest arrival of the period was on 5 January 2026, 2 hours 48 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in January 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 5 January 2026 | 2 hours 48 minutes | Carrier |
| 29 January 2026 | 2 hours 15 minutes | Carrier |
| 6 September 2025 | 2 hours 5 minutes | Late-arriving aircraft |
| 22 January 2026 | 2 hours 5 minutes | Carrier |
| 30 September 2025 | 2 hours 4 minutes | Carrier |
Delay causes
Why Delta runs late on this route
National Airspace System accounts for 44% of the 2,305 delay minutes carriers reported here, and the remaining four split what is left.
- 44%National Airspace System
- 42%Carrier
- 14%Late-arriving aircraft
The largest share of delay minutes, 42%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 972 of the 2,305 delay minutes reported here. The split is drawn from 2,305 reported delay minutes.
44% 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 1,009 minutes out of 2,305, against a national NAS share of 21%.
Cancellations are rare at 0.83%, 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 costs
Badly late arrivals are rare here: only 2.8% 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 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 78.7% on time across 363 flights, 6 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 6 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 84.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 357 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 SEA68.3%
- 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
- The best day of the week to fly, and why it is the second lever
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.