Route profile
PIT→SEA
Flight reliability, delays and best times to fly from Pittsburgh to Seattle, 2,125 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 54% of comparable major US routes (4,598 compared)
Calculated from 1,476 flights. How this is calculated · What counts as on time
PIT → SEA arrives on time 77.0% of the time; the return trip, SEA → PIT, arrives on time 77.8% of the time.
PIT → SEA spends 29.2 minutes on the ground on a 2,125-mile trip: 16.2 minutes from pushback to wheels-up at PIT and 13.0 minutes from touchdown to gate at SEA.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What sets this route apart
Where PIT to SEA differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
PIT to SEA is at its best against routes of similar length for flights scheduled at 9 AM: 89.7% arrive on time, 7.9 points ahead of the 81.8% those routes manage at that hour.
Thursday is the day PIT to SEA slips furthest against routes of similar length, 71.4% on time where they average 77.8%, 6.4 points lower.
In June, PIT to SEA runs 12.2 points below routes of similar length, 62.2% on time to 74.4%. Against all other routes the gap is 10.5 points.
PIT to SEA against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 9 AM departures | 89.7% | routes of similar length | 81.8% | +7.9 pts | 146 here, 71,452 there |
| Weekday: Thursday | 71.4% | routes of similar length | 77.8% | −6.4 pts | 206 here, 149,264 there |
| Month: June | 62.2% | routes of similar length | 74.4% | −12.2 pts | 180 here, 91,130 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 2,125 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
40 min late
against a median of 6 min early
Percentiles over 1,476 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SEA after arriving from PIT.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 39% | Likely to miss |
| 45 min | 22% | High risk |
| 60 min | 13% | Some risk |
| 90 min | 5.7% | Some risk |
| 120 min | 3.4% | 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 1.56% of the time and diverts 0.14% of the time, which a late arrival never shows up in.
Chance of missing is the share of 1,451 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 40 minutes late (90th-percentile gate arrival delay), over 1,476 operations.
Any other layover length: connection checker.
Best time to fly
PIT → SEA flights departing 9 AM–12 PM arrived on time 89.7% of the time, against 71.2% for 6–9 PM departures, a gap of 18.5 percentage points.
By departure window
By departure hour
- 12 AM to 6 AM: too few flights to score
- 7 AM: 86.3% on time from 289 flights
- 8 AM: 79.6% on time from 160 flights
- 9 AM: 89.7% on time from 148 flights
- 10 AM to 5 PM: too few flights to score
- 6 PM: 76.5% on time from 444 flights
- 7 PM: 65.9% on time from 434 flights
- 8 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why PIT → 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 PIT → SEA. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on PIT → SEA, at 46.0%: flights here mostly leave late because the plane came in late, and the day shows it: 9 AM–12 PM departures arrived on time 89.7% of the time and 6–9 PM departures 71.2%.
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 | 1,475 | 77.0% | 1.56% | -6 min | 5.7% |
Weekly and seasonal patterns
By day of week
Wednesday is historically the most reliable day and Thursday the least, a gap of 11.3 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 73.8% against 74.9% in the 12 months before — broadly unchanged.
Data and methodology
Calculated by FlyerIntel from 1,476 PIT → 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