Carrier route record
DLSEA→TPA
Delta Air Lines · Seattle to Tampa
- 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 SEA to TPA lands a B+, about a point better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 363 flights, with a median arrival 3 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Delta on SEA to TPA from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.7%
Arrivals under 15 minutes late, of 357 completed flights
Avg delay
57 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.89%
Whole route
80.4%
Every carrier on SEA to TPA, 975 flights
These figures cover 363 flights between September 2025 and August 2026. The median arrival is 3 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 SEA to TPA
Delta flew 363 of the 975 flights on SEA to TPA, about 37% of it. Its 78.7% on time is 2 points worse than the route as a whole, which runs 80.4%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Alaska at 81.3% to Delta at 78.7%.
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 |
|---|---|---|---|---|---|
| Alaska Airlines | 612 | 81.3% | 48 min | 0.49% | B+ |
| Delta Air Lines (this page)thin sample | 363 | 78.7% | 57 min | 0.55% | B+ |
Flight by flight
Delta flight numbers on SEA to TPA
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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.
There are not enough flights in each departure window to split Delta's SEA to TPA record by time of day without the percentages moving on noise. The headline rate of 78.7% is the reliable figure here.
Across the year
Delta on SEA to TPA through the year
July is the worst month at 66.7% on time, 23 points below April, the best at 90.0%. 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, Saturday is the strongest day at 88.2% on time and Sunday the weakest at 72.0%, a spread of 16 points.
Arrival by arrival
How late Delta on SEA to TPA runs when it is late
The 76 late arrivals split 29 under half an hour, 24 between 30 and 60 minutes, and 23 an hour or more.
- 15+ min early82 flights23.0%
- Within 15 min199 flights55.7%
- 15–29 min late29 flights8.1%
- 30–59 min late24 flights6.7%
- 1–2 hours late16 flights4.5%
- 2+ hours late7 flights2.0%
Scale runs 0% to 100%.
Share of 357 completed flights by arrival against schedule.
A late pushback is often recovered here: of 71 departures that left 15 minutes late or more, 24 still arrived on time. In the other direction, 29 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 TPA.
The worst days
Worst days for Delta on SEA to TPA
The latest arrival of the period was on 13 March 2026, 9 hours 17 minutes behind schedule; most of its delay minutes were filed as extreme weather. The five worst days are spread across March, September, February and November, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 13 March 2026 | 9 hours 17 minutes | Extreme weather |
| 29 September 2025 | 2 hours 38 minutes | Carrier |
| 16 March 2026 | 2 hours 29 minutes | Late-arriving aircraft |
| 1 February 2026 | 2 hours 22 minutes | Carrier |
| 17 November 2025 | 2 hours 9 minutes | National Airspace System |
Delay causes
Why Delta 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 4,295 reported delay minutes.
- 41%Carrier
- 28%National Airspace System
- 17%Extreme weather
- 14%Late-arriving aircraft
Extreme weather accounts for 17% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.8 times the usual weather exposure. The split is drawn from 4,295 reported delay minutes.
The largest share of delay minutes, 41%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,740 of the 4,295 delay minutes reported here.
Cancellations are rare at 0.55%, 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
6.4% 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 about an hour, 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 84.3% on time across 363 flights, 6 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 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 SEA to TPA
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 78.7% 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
- SEA to TPA, every carrier
- Delta on TPA to SEA, the return leg
- Alaska Airlines on SEA to TPA81.3%
- Delta Air Lines network-wide record
- Seattle-Tacoma International (SEA) delay statistics
- Tampa International (TPA) 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.