Route · SEA → PHL · 2020–2025 BTS data
Seattle to Philadelphia
The SEA–PHL corridor (Seattle, WA → Philadelphia, PA) runs ahead of the national average, served by 3 carriers across roughly 2,378 miles.
Data updated 2026-06-13
- 79.2%
- On-time
- +0.2 pts
- vs US avg
- 61 min
- Delay when late
- 5,534
- Flights
Cancelled
1.2%
Best Month
Mar 2025 89%
Worst Month
Aug 2024 50%
Distance
2,378 mi
Carriers
3
Monthly Performance
Recent 24 months of route data.
| Period | Flights | Delayed | Cancelled | Diverted | Carriers |
|---|---|---|---|---|---|
| Dec 2025 | 93 | 18 | 1 | 0 | AS,AA |
| Nov 2025 | 87 | 13 | 0 | 1 | AA,AS |
| Oct 2025 | 123 | 16 | 2 | 0 | AA,AS |
| Sep 2025 | 121 | 24 | 0 | 1 | AA,AS |
| Aug 2025 | 136 | 38 | 1 | 0 | AA,AS |
| Jul 2025 | 123 | 38 | 6 | 2 | AA,AS |
| Jun 2025 | 116 | 40 | 0 | 0 | AA,AS |
| May 2025 | 93 | 34 | 0 | 0 | AA,AS |
| Apr 2025 | 82 | 17 | 0 | 0 | AA,AS |
| Mar 2025 | 72 | 8 | 0 | 0 | AA,AS |
| Feb 2025 | 36 | 3 | 0 | 0 | AA,AS |
| Jan 2025 | 38 | 4 | 0 | 0 | AA,AS |
| Dec 2024 | 86 | 21 | 0 | 0 | AA,AS |
| Nov 2024 | 74 | 10 | 0 | 0 | AS,AA |
| Oct 2024 | 77 | 22 | 0 | 0 | AS,AA |
| Sep 2024 | 91 | 37 | 0 | 0 | AA,AS |
| Aug 2024 | 124 | 62 | 6 | 2 | AA,AS |
| Jul 2024 | 123 | 56 | 1 | 1 | AA,AS |
| Jun 2024 | 116 | 42 | 2 | 0 | AA,AS |
| May 2024 | 93 | 24 | 0 | 0 | AA,AS |
| Apr 2024 | 85 | 19 | 0 | 0 | AA,AS |
| Mar 2024 | 73 | 14 | 0 | 1 | AA,AS |
| Feb 2024 | 54 | 11 | 0 | 0 | AA,AS |
| Jan 2024 | 59 | 21 | 8 | 0 | AA,AS |
Cancellation Rate
1.2%
27 of 2,175 flights
Diversion Rate
0.4%
8 of 2,175 flights
Explore origin & destination
On-time and delay data for the airports this route connects.
SEA - Seattle
Full on-time, delay-cause, and seasonal performance for Seattle, WA.
Origin airport →PHL - Philadelphia
Full on-time, delay-cause, and seasonal performance for Philadelphia, PA.
Destination airport →Compare the two airports
See SEA and PHL side by side on delays, cancellations, and reliability.
Open comparison tool →Similar routes
Other BTS-tracked routes with comparable performance or trip length to SEA–PHL.
Routes with a similar on-time rate
What the Data Says About SEA to PHL
5,534 tracked flights put the SEA to PHL pairing (Seattle to Philadelphia) at a 79.2% on-time rate, squarely in line with the wider network. Delays that do occur run 60.8 minutes on average. Across the 2,378-mile route and its 3 carriers, the trailing 24 months show 1.2% cancelled and 0.4% diverted (2,175 flights sampled).
The monthly split is wide on this route: Mar 2025 posted the strongest performance at 89% on-time, while Aug 2024 came in at just 50% - a 39-point swing worth factoring into travel timing.
Frequently Asked Questions
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Data source
Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.
Read our methodology - how this data is sourced, computed, and verified.
Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.