Carrier route record
DLSEA→TUS
Delta Air Lines · Seattle to Tucson
- Flights
- 138
- Period
- September 2025 to August 2026
- Share of route
- 13%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on SEA to TUS lands a B, 7 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 138 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 371 at 88.1% on time.
Set against the rest of the country, Delta's SEA to TUS record is 7 points better than the US average of 77.3%. That gap is worth roughly 65 fewer late arrivals for every thousand flights.
Key figures
On time
83.8%
Arrivals under 15 minutes late, of 136 completed flights
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
1.45%
National rate is 1.89%
Whole route
82.5%
Every carrier on SEA to TUS, 1,065 flights
These figures cover 138 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 SEA to TUS
Delta flew 138 of the 1,065 flights on SEA to TUS, about 13% of it. Its 83.8% on time is about level with the route as a whole at 82.5%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from SkyWest at 88.1% to Alaska at 78.5%.
The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 88.1% of the time; Alaska Airlines manages 78.5%. Sample sizes sit next to every figure, because a two-point gap across 556 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 371 | 88.1% | 62 min | 0.00% | A+ |
| Delta Air Lines (this page)thin sample | 138 | 83.8% | 73 min | 1.45% | B |
| Alaska Airlines | 556 | 78.5% | 38 min | 0.54% | B+ |
SkyWest leads Alaska by 10 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
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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 138 flights.
There are not enough flights in each departure window to split Delta's SEA to TUS record by time of day without the percentages moving on noise. The headline rate of 83.8% is the reliable figure here.
Across the year
Delta on SEA to TUS through the year
- Oct–Dec 202512 flights—
- Jan–Mar 202690 flights77.3%
- Apr–Jun 202636 flights97.2%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 83.8% on time across 138 flights.
Split by quarter, Delta on SEA to TUS logged 12 flights in Oct–Dec 2025, 90 flights in Jan–Mar 2026 and 36 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 83.8% annual figure is the one to use.
Arrival by arrival
How late Delta on SEA to TUS runs when it is late
Delta on SEA to TUS often beats the schedule: 38 of 136 completed flights, 28%, arrived 15 minutes or more early. Most of the lateness is short. 11 of the 22 late arrivals were under half an hour behind, and 6 reached an hour or more.
- 15+ min early38 flights27.9%
- Within 15 min76 flights55.9%
- 15–29 min late11 flights8.1%
- 30–59 min late5 flights3.7%
- 1–2 hours late1 flights0.7%
- 2+ hours late5 flights3.7%
Scale runs 0% to 100%.
Share of 136 completed flights by arrival against schedule.
6 of 21 late departures made up the time and arrived on time, 29% of them. In the other direction, 7 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 TUS.
The worst days
Worst days for Delta on SEA to TUS
The latest arrival of the period was on 6 January 2026, 4 hours 59 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 6 January 2026 | 4 hours 59 minutes | Carrier |
| 13 March 2026 | 4 hours 35 minutes | Extreme weather |
| 25 January 2026 | 3 hours 53 minutes | Carrier |
| 19 April 2026 | 2 hours 26 minutes | Late-arriving aircraft |
| 6 March 2026 | 2 hours 12 minutes | Carrier |
Delay causes
Why Delta runs late on this route
Carrier accounts for 57% of the 1,612 delay minutes carriers reported here, and the remaining four split what is left.
- 57%Carrier
- 18%Late-arriving aircraft
- 15%National Airspace System
- 10%Extreme weather
The largest share of delay minutes, 57%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 921 of the 1,612 delay minutes reported here. The split is drawn from 1,612 reported delay minutes.
Cancellations sit at 1.45% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 4.4% 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.
The 1,215 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg is a different operation and performs like one: it runs 89.0% on time across 138 flights, 5 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 5 points of difference.
One caution: this is a thin sample. 138 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 TUS
Put together: treat all of this as provisional. 138 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 83.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 136 completed flights over 12 months sit behind that.
Related
Where to go next
- SEA to TUS, every carrier
- Delta on TUS to SEA, the return leg
- SkyWest Airlines on SEA to TUS88.1%
- Alaska Airlines on SEA to TUS78.5%
- Delta Air Lines network-wide record
- Seattle-Tacoma International (SEA) delay statistics
- Late aircraft, weather, or the airline: what actually causes US flight delays
- How to read this site: grades, sample sizes, and honest caveats
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.