Route profile
DAL→SEA
Flight reliability, delays and best times to fly from Dallas to Seattle, 1,670 miles.
Right now
Aviation weather is not currently a factor.
Weather conditions are strongly associated with delays and cancellations.
Route reliability
July 2023 – July 2026
Better than 70% of comparable major US routes (4,598 compared)
Calculated from 1,037 flights. How this is calculated · What counts as on time
DAL → SEA arrives on time 78.0% of the time; the return trip, SEA → DAL, arrives on time 71.2% of the time, a 6.8-point gap between the two directions of the same city pair.
DAL → SEA spends 26.4 minutes on the ground on a 1,670-mile trip: 15.4 minutes from pushback to wheels-up at DAL and 11.1 minutes from touchdown to gate at SEA.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
Which day you fly matters unusually much here, a wider weekday spread than 92% of 4,467 comparable routes.
85.8% on time on a typical Monday, against 71.7% on a Sunday.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 4,467 in the comparison.
What sets this route apart
Where DAL to SEA differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
DAL to SEA is at its best against routes of similar length for flights scheduled at 2 PM: 84.3% arrive on time, 10.9 points ahead of the 73.4% those routes manage at that hour. Against all other routes the gap is 9.7 points.
DAL to SEA holds up on Mondays better than routes of similar length do: 85.8% on time to their 76.9%, a 8.9 points lead. Against all other routes the gap is 8.6 points.
Alaska Airlines does better on DAL to SEA than on its routes of similar length: 83.3% on time here, 77.4% there, 5.9 points apart. Against all other routes the gap is 5.3 points.
DAL to SEA against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 2 PM departures | 84.3% | routes of similar length | 73.4% | +10.9 pts | 452 here, 75,544 there |
| Weekday: Monday | 85.8% | routes of similar length | 76.9% | +8.9 pts | 141 here, 221,188 there |
| Airline: Alaska Airlines | 83.3% | routes of similar length | 77.4% | +5.9 pts | 682 here, 112,221 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 1,670 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
When it goes wrong
July 2023 – July 2026
30 min late
against a median of 3 min early
Percentiles over 1,037 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SEA after arriving from DAL.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 41% | Likely to miss |
| 45 min | 21% | High risk |
| 60 min | 10% | Some risk |
| 90 min | 3.9% | Low risk |
| 120 min | 2.2% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 1.16% of the time and diverts 0.77% of the time, which a late arrival never shows up in.
Chance of missing is the share of 1,017 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 30 minutes late (90th-percentile gate arrival delay), over 1,037 operations.
Any other layover length: connection checker.
Best time to fly
DAL → SEA flights departing 12–3 PM arrived on time 84.3% of the time, against 68.2% for 6–9 PM departures, a gap of 16.1 percentage points.
By departure window
By departure hour
- 12 AM to 6 AM: too few flights to score
- 7 AM: 87.8% on time from 123 flights
- 8 AM to 1 PM: too few flights to score
- 2 PM: 84.3% on time from 463 flights
- 3 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why DAL → SEA runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding and fueling, all within the carrier’s control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for DAL → SEA. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on DAL → SEA, at 44.8%: flights here mostly leave late because the plane came in late, and the day shows it: 12–3 PM departures arrived on time 84.3% of the time and 6–9 PM departures 68.2%.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Alaska Airlines | 700 | 83.3% | 1.43% | -7 min | 2.3% |
| Southwest Airlines | 337 | 67.2% | 0.59% | 5 min | 7.8% |
Alaska Airlines flew 67.5% of the 1,037 flights listed.
Alaska Airlines arrived on time 16.1 percentage points more often than Southwest Airlines on this route.
Other ways to fly Dallas–Fort Worth to Seattle
Airport pairs in the same two city markets, as the DOT defines them.
| Route | Flights | On time | Cancelled | Median delay | Score |
|---|---|---|---|---|---|
| DFW→SEA Dallas–Fort Worth to Seattle | 15,630 | 71.5% | 1.70% | -1 min | 52 |
| DAL→SEA this route Dallas to Seattle | 1,037 | 78.0% | 1.16% | -3 min | 73 |
DAL → SEA is the most reliable pairing for this journey at 78.0% on time, against 71.5% for DFW → SEA.
Flying to SEA from the Dallas–Fort Worth area? Compare DAL, DFW for SEA, with the same test for what counts as a real difference.
Weekly and seasonal patterns
By day of week
Monday is historically the most reliable day and Sunday the least, a gap of 14.1 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-04 to 2026-07), on-time arrivals averaged 70.2% against 75.3% in the 12 months before — declining by 5.1 percentage points.
Data and methodology
Calculated by FlyerIntel from 1,037 DAL → SEA flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed