Route profile
SEA→SAT
Flight reliability, delays and best times to fly from Seattle to San Antonio, 1,774 miles.
Right now
Weather conditions are strongly associated with delays and cancellations.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 75% of comparable major US routes (4,598 compared)
Calculated from 1,782 flights. How this is calculated · What counts as on time
SEA → SAT arrives on time 75.6% of the time; the return trip, SAT → SEA, arrives on time 73.7% of the time.
SEA → SAT spends 26.4 minutes on the ground on a 1,774-mile trip: 20.9 minutes from pushback to wheels-up at SEA and 5.5 minutes from touchdown to gate at SAT.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
Unlike most, it barely matters what time you fly this route, a steadier spread than 96% of 4,023 comparable routes.
77.8% on time for 9 PM–5 AM departures, against 71.5% for 9 AM–12 PM, a narrow gap either way.
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 4,023 in the comparison.
What sets this route apart
Where SEA to SAT differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
SEA to SAT struggles most at 11 AM: 71.2% of its flights scheduled then arrive on time, 7.2 points behind the 78.4% on routes of similar length at the same hour. Against all other routes the gap is 9.8 points.
In August, SEA to SAT runs 11.4 points below routes of similar length, 64.5% on time to 75.9%. Against all other routes the gap is 12 points.
May is kinder to SEA to SAT than to routes of similar length: 83.2% on time against 75.7%, 7.5 points better. Against all other routes the gap is 8 points.
SEA to SAT against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 11 AM departures | 71.2% | routes of similar length | 78.4% | −7.2 pts | 302 here, 78,908 there |
| Month: August | 64.5% | routes of similar length | 75.9% | −11.4 pts | 155 here, 112,661 there |
| Month: May | 83.2% | routes of similar length | 75.7% | +7.5 pts | 173 here, 111,461 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 1,774 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
34 min late
against a median of 1 min early
Percentiles over 1,782 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SAT after arriving from SEA.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 46% | Likely to miss |
| 45 min | 23% | High risk |
| 60 min | 12% | Some risk |
| 90 min | 3.1% | Low risk |
| 120 min | 1.5% | 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 0.56% of the time and diverts 0.11% of the time, which a late arrival never shows up in.
Chance of missing is the share of 1,770 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 34 minutes late (90th-percentile gate arrival delay), over 1,782 operations.
Any other layover length: connection checker.
Best time to fly
SEA → SAT flights departing 9 PM–5 AM arrived on time 77.8% of the time, against 71.5% for 9 AM–12 PM departures, a gap of 6.3 percentage points.
By departure window
By departure hour
- 12 AM to 10 AM: too few flights to score
- 11 AM: 71.2% on time from 304 flights
- 12 PM: 74.6% on time from 581 flights
- 1 PM to 10 PM: too few flights to score
- 11 PM: 80.1% on time from 530 flights
Departure windows with fewer than 120 flights are not scored.
Why SEA → SAT runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
screening or terminal security incidents
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for SEA → SAT. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on SEA → SAT, at 42.6%: flights here mostly leave late because the plane came in late, though departure time makes little difference here: the best and worst windows are 6 points apart.
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 | 1,782 | 75.6% | 0.56% | -1 min | 3.2% |
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
| Flight | Scheduled | Operations | On time |
|---|---|---|---|
| AS494 Alaska Airlines | 12:35 PM | 1,066 | 73.9% |
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Sunday the least, a gap of 10.2 percentage points.
By month
- Jan to Feb: no data
- Mar: 80.5%
- Apr: 81.3%
- May: 83.2%
- Jun: 65.6%
- Jul: 67.4%
- Aug: 64.5%
- Sep: 81.9%
- Oct: 77.1%
- Nov: 82.3%
- Dec: 75.4%
August is historically the weakest month and May the strongest, a spread of 18.7 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 75.7% against 73.0% in the 12 months before — improving by 2.7 percentage points.
Data and methodology
Calculated by FlyerIntel from 1,782 SEA → SAT 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