Routes › San Francisco (SFO) › SFO to SEA
Route · 12 months to July 2026
San Francisco to Seattle: on-time record
San Francisco International to Seattle/Tacoma International
BTS: A flight is counted as on time if it arrived less than 15 minutes after its scheduled time. Only carriers with at least 0.5 percent of domestic scheduled passenger revenue report. Data through July 2026; this is a monthly history, not live flight status.
Flights from San Francisco (SFO) to Seattle (SEA) arrived on time 72.3% of the time in the 12 months to July 2026. Reporting carriers scheduled 6,797 flights on the route in that period, about 19 a day, a distance of 679 miles.
That is 3.7 points below the national on-time share of 76.0% for the same period and 3.3 points below the 75.6% recorded for all departures from SFO. Flights that did arrive were 7.7 min late on average, and 1.1% of scheduled flights were cancelled (national: 1.8%).
4 reporting carriers flew the route at least 60 times. Delta Air Lines had the highest on-time share at 79.9% of 955 flights; Alaska Airlines had the lowest at 68.7% of 2,713.
By scheduled departure hour (local time at SFO), flights leaving from 5 am to 6 am had the highest on-time share, 94.8%; those leaving from 8 am to 9 am had the lowest, 55.8%.
The on-time share is down 3.2 points on the previous 12 months (75.5%); cancellations moved from 1.0% to 1.1%.
Of the delay minutes that carriers assigned to a BTS cause category on this route, late-arriving aircraft 47%, air carrier 28% and national aviation system 22%.
- On time 72.3%
- Arrived 15+ minutes late 26.5%
- Cancelled 1.1%
- Diverted 0.1%
Airlines on the route compared
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| AS Alaska Airlines | 2,713 | 40% | 68.7% | 10.8 min | 1.3% |
| UA United Airlines | 2,053 | 30% | 75.2% | 6.2 min | 0.4% |
| OO SkyWest Airlines | 1,073 | 16% | 69.4% | 8.4 min | 1.1% |
| DL Delta Air Lines | 955 | 14% | 79.9% | 1.6 min | 1.7% |
Carriers with at least 24 flights in the 12 months to July 2026. The on-time pill is green when a carrier is at or above the route's overall share. Regional carriers operate flights sold under larger airlines' brands; BTS lists the carrier that operated the flight.
Compared with the airports and the nation
| Measure | SFO to SEA | All departures from SFO | All arrivals at SEA | All reported flights |
|---|---|---|---|---|
| Arrived on time | 72.3% | 75.6% | 78.8% | 76.0% |
| Arrived 15+ minutes late | 26.5% | 23.1% | 20.0% | 21.9% |
| Cancelled | 1.1% | 1.0% | 1.1% | 1.8% |
| Diverted | 0.1% | 0.3% | 0.1% | 0.3% |
| Average arrival delay | 7.7 min | 7.8 min | 3.1 min | 8.1 min |
| Delay minutes per 100 flights | 1,612 | 1,667 | 1,281 | 1,684 |
| Scheduled flights | 6,797 | 147,566 | 164,830 | 7,043,858 |
12 months to July 2026. Delay minutes count late arrivals only (an early arrival is zero), so the per-100-flights row is a normalised total rather than an average of early and late.
The return direction, SEA to SFO, recorded 61.4% on time across 6,791 flights in the same period.
Month by month
Year on year: on time 72.3% against 75.5% (−3.2 pts), cancelled 1.1% against 1.0%, flights 6,797 against 6,941.
By scheduled departure hour
Delay causes
Seasonality
| Calendar month | Flights | On time | Cancelled | Avg arrival delay | Years in sample |
|---|---|---|---|---|---|
| Jan | 1,500 | 80.9% | 4.0% | 0.6 min | 3 |
| Feb | 1,408 | 80.1% | 1.3% | 1.7 min | 3 |
| Mar | 1,602 | 77.2% | 1.3% | 4.4 min | 3 |
| Apr | 1,551 | 75.0% | 0.3% | 5.1 min | 3 |
| May | 1,777 | 67.5% | 0.6% | 10.1 min | 3 |
| Jun | 1,787 | 64.0% | 0.6% | 14.1 min | 3 |
| Jul | 1,929 | 65.6% | 1.7% | 12.7 min | 3 |
| Aug | 1,864 | 74.6% | 1.1% | 7.3 min | 3 |
| Sep | 1,767 | 78.5% | 0.6% | 1.8 min | 3 |
| Oct | 1,707 | 81.0% | 0.6% | -1.4 min | 3 |
| Nov | 1,630 | 81.8% | 1.3% | 0.5 min | 3 |
| Dec | 1,634 | 76.3% | 0.7% | 7.7 min | 3 |
Each calendar month summed across the 36 months on file, so most rows combine three years. The pill compares the month with the route's own 12-month share.
Other routes from San Francisco (SFO)
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| SFO–LAX | San Francisco to Los Angeles | 11,235 | 72.1% | 10.5 min | 0.9% |
| SFO–JFK | San Francisco to New York | 6,769 | 77.4% | 4.1 min | 2.2% |
| SFO–SAN | San Francisco to San Diego | 6,621 | 63.9% | 17.5 min | 1.2% |
| SFO–LAS | San Francisco to Las Vegas | 6,118 | 72.1% | 12.1 min | 0.7% |
| SFO–ORD | San Francisco to Chicago | 5,617 | 74.6% | 10.2 min | 1.2% |
| SFO–DEN | San Francisco to Denver | 5,461 | 74.8% | 7.5 min | 0.4% |
| SFO–BOS | San Francisco to Boston | 4,733 | 74.5% | 7.8 min | 1.7% |
| SFO–SNA | San Francisco to Santa Ana | 4,716 | 77.9% | 5.5 min | 1.3% |
All 84 routes and the airport record for SFO · airport record for SEA
Questions and answers
How often are flights from San Francisco to Seattle on time?
72.3% of the 6,797 flights scheduled from SFO to SEA in the 12 months to July 2026 arrived less than 15 minutes after their scheduled time. The national share for the same period was 76.0%. Cancelled and diverted flights count as not on time.
Which airline has the highest on-time share from SFO to SEA?
Among reporting carriers with at least 60 flights on the route, Delta Air Lines had the highest on-time share (79.9%), followed by United Airlines (75.2%) and SkyWest Airlines (69.4%). Differences of a point or two on a few hundred flights are small.
What causes delays between San Francisco and Seattle?
For flights that arrived 15 or more minutes late, carriers attributed the delay minutes as follows: late-arriving aircraft 47%, air carrier 28%, national aviation system 22%, extreme weather 4%, security 0%. The categories are the carriers' own reports to BTS; weather that slows the wider system is usually recorded under the National Aviation System rather than extreme weather.
What time of day has the highest on-time share from SFO?
Flights scheduled to leave SFO from 5 am to 6 am arrived on time 94.8% of the time, the highest of any hour with enough flights to compare. The lowest was 8 am to 9 am at 55.8%. Delays tend to build through the day as late aircraft carry over to later flights.
Is it getting better?
The on-time share for the 12 months to July 2026 was 72.3%, down 3.2 points on the previous 12 months (75.5%). The monthly chart on this page shows each of the last 36 months. Across those months, November had the highest on-time share (81.8%) and June the lowest (64.0%).
Where does this data come from?
Every figure is computed from the Bureau of Transportation Statistics Reporting Carrier On-Time Performance files, which list each scheduled domestic flight by the carriers required to report. This page covers August 2023 to July 2026. It shows totals and averages only; it is not a live flight-status service.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance (1987 to present), monthly files August 2023 to July 2026, a US government work in the public domain. Figures are totals and averages over all scheduled flights by reporting carriers on the route; no individual flight or aircraft is identified. Times are local to the departure airport. The load factor and passenger counts from the BTS T-100 series are not included in this edition. See the methodology; report processing errors through corrections.