Flight number record
AS 654
Alaska Airlines · Ontario to Seattle
- Route
- ONT → SEA
- Departs
- 12:04
- Flights
- 310
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AS 654, check with Alaska Airlines.
AS 654 earns an A−. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 10 points better than the national rate of 77.3%. When something does go wrong the average delay runs about 40 minutes. That rests on 310 flights, with a median arrival 9 minutes early.
Set against the rest of the country, AS 654's record is 10 points better than the US average of 77.3%. That gap is worth roughly 100 fewer late arrivals for every thousand flights.
Key figures
On time
87.3%
Arrivals under 15 minutes late, of 299 completed flights
Avg delay
40 min
Across delayed arrivals only, not all flights
Cancelled
3.55%
National rate is 1.89%
1 hour+ late
3.0%
National rate is 8.3%
These figures cover 310 flights between September 2025 and August 2026. The median arrival is 9 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Schedule
When AS 654 flies
AS 654 flies ONT to SEA without a single fixed slot. Its most common scheduled departure was 12:04, used on 84 of 310 flights, with 11:53 (36 flights) and 10:33 (35 flights) next.
- Departs 12:0484 flights27.1%
- Departs 11:5336 flights11.6%
- Departs 10:3335 flights11.3%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 12:04 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and AS 654 runs 9 points better at 87.3%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
AS 654 next to ONT to SEA
Every carrier on ONT to SEA combined arrived on time 85.9% of the time across 2,488 flights, so AS 654 is about level with it. Alaska flew 1,257 flights on the same city pair under all its flight numbers, including this one, and those ran 82.2% on time. Across its whole network Alaska Airlines managed 79.7%, which this flight beats by 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 654thin sample | 310 | 87.3% | 40 min | 3.55% | A− |
| All Alaska Airlines on ONT–SEA | 1,257 | 82.2% | 53 min | 1.75% | B |
| All carriers on ONT–SEA | 2,488 | 85.9% | 67 min | 1.13% | A |
| Alaska Airlines, whole network | 309,844 | 79.7% | 52 min | 1.20% | B |
Across the year
AS 654 quarter by quarter
AS 654 did not run the same all year. Its best quarter was Jan–Mar 2026 at 90.9% on time and its weakest Jul–Sep 2026 at 80.3%, a swing of 11 points on roughly 78 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Oct–Dec 202567 flights87.3%
- Jan–Mar 202690 flights90.9%
- Apr–Jun 202691 flights88.5%
- Jul–Sep 202662 flights80.3%
Scale runs 70% to 95%.
By weekday, AS 654 ranged from 83.3% on Saturday to 90.9% on Sunday. With about 44 flights behind each day, a spread of 8 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late AS 654 runs when it is late
AS 654 often beats the schedule: 109 of 299 completed flights, 36%, arrived 15 minutes or more early. The 38 late arrivals split 18 under half an hour, 11 between 30 and 60 minutes, and 9 an hour or more. Not one arrived two hours late.
- 15+ min early109 flights36.5%
- Within 15 min152 flights50.8%
- 15–29 min late18 flights6.0%
- 30–59 min late11 flights3.7%
- 1–2 hours late9 flights3.0%
- 2+ hours late0 flights0.0%
Scale runs 0% to 100%.
Share of 299 completed flights by arrival against schedule.
A late pushback is often recovered here: of 52 departures that left 15 minutes late or more, 21 still arrived on time. 7 flights left on time and still arrived late.
The worst days
Worst days for AS 654
The latest arrival of the period was on 14 March 2026, 1 hour 43 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 14 March 2026 | 1 hour 43 minutes | Carrier |
| 15 March 2026 | 1 hour 38 minutes | Late-arriving aircraft |
| 31 December 2025 | 1 hour 33 minutes | Late-arriving aircraft |
| 5 January 2026 | 1 hour 22 minutes | Carrier |
| 19 December 2025 | 1 hour 19 minutes | Carrier |
Delay causes
Why AS 654 runs late
Late-arriving aircraft accounts for 43% of the 1,513 delay minutes carriers reported here, and the remaining four split what is left.
- 43%Late-arriving aircraft
- 41%Carrier
- 13%National Airspace System
- 4%Extreme weather
43% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 1,513 reported delay minutes here, that single category outweighs weather by 11 to one. The split is drawn from 1,513 delay minutes reported on AS 654.
Cancellations run at 3.55%, against 1.89% nationally. That is about one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 3.0% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 956 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
Every one of the 310 flights under AS 654 in the data flew ONT to SEA. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 310 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking AS 654
For a booking, the cancellation rate is the figure to plan around on AS 654: 3.55% of its 310 scheduled flights did not operate. A late arrival costs about 40 minutes, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- ONT to SEA, every carrier and departure
- SEA to ONT, the return direction
- SkyWest Airlines 4031 on the same route88.5%
- Alaska Airlines 607 on the same route93.5%
- Ontario International (ONT) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Alaska Airlines on-time record
- Every Alaska Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means Alaska Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.