Flight number record
AS 31
Alaska Airlines · New York to Seattle
- Route
- JFK → SEA
- Departs
- 16:29
- Flights
- 363
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AS 31, check with Alaska Airlines.
AS 31 sits in the middle of the pack with a C−. About seven flights in ten arrive on time by the DOT's definition, 5 points worse than the national rate of 77.3%. The late ones land a little over an hour behind schedule. That rests on 363 flights, with a median arrival 3 minutes early.
The national on-time rate over the same period is 77.3%, so AS 31 runs 5 points behind the country as a whole. Across a thousand flights that is about 54 extra late arrivals.
Key figures
On time
71.9%
Arrivals under 15 minutes late, of 345 completed flights
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
4.68%
National rate is 1.89%
1 hour+ late
9.3%
National rate is 8.3%
These figures cover 363 flights between September 2025 and August 2026. Beyond the headline rate, 9.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When AS 31 flies
AS 31 flies JFK to SEA without a single fixed slot. Its most common scheduled departure was 16:29, used on 142 of 363 flights, with 16:51 (48 flights) next.
- Departs 16:29142 flights39.1%
- Departs 16:5148 flights13.2%
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 16:29 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and AS 31 runs level with that at 71.9%. 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 31 next to JFK to SEA
Every carrier on JFK to SEA combined arrived on time 69.5% of the time across 2,906 flights, so AS 31 is 2 points ahead of it. Alaska flew 1,401 flights on the same city pair under all its flight numbers, including this one, and those ran 68.1% on time. Across its whole network Alaska Airlines managed 79.7%, which this flight trails by 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 31thin sample | 363 | 71.9% | 71 min | 4.68% | C− |
| All Alaska Airlines on JFK–SEA | 1,401 | 68.1% | 65 min | 3.35% | C− |
| All carriers on JFK–SEA | 2,906 | 69.5% | 65 min | 3.44% | C− |
| Alaska Airlines, whole network | 309,844 | 79.7% | 52 min | 1.20% | B |
Across the year
AS 31 quarter by quarter
AS 31 did not run the same all year. Its best quarter was Jul–Sep 2025 at 86.7% on time and its weakest Jan–Mar 2026 at 62.1%, a swing of 25 points on roughly 73 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.
- Jul–Sep 202530 flights86.7%
- Oct–Dec 202591 flights62.2%
- Jan–Mar 202690 flights62.1%
- Apr–Jun 202690 flights85.4%
- Jul–Sep 202662 flights71.9%
Scale runs 55% to 90%.
By weekday, AS 31 did best on Saturday at 83.3% on time and worst on Sunday at 62.5%. Each day rests on about 52 flights, so a gap of 21 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late AS 31 runs when it is late
AS 31 often beats the schedule: 105 of 345 completed flights, 30%, arrived 15 minutes or more early. The 97 late arrivals split 34 under half an hour, 31 between 30 and 60 minutes, and 32 an hour or more.
- 15+ min early105 flights30.4%
- Within 15 min143 flights41.4%
- 15–29 min late34 flights9.9%
- 30–59 min late31 flights9.0%
- 1–2 hours late15 flights4.3%
- 2+ hours late17 flights4.9%
Scale runs 0% to 100%.
Share of 345 completed flights by arrival against schedule.
22 of 81 late departures made up the time and arrived on time, 27% of them. In the other direction, 38 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at SEA.
The worst days
Worst days for AS 31
The latest arrival of the period was on 6 September 2025, 6 hours 12 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On three of the five worst days the largest share was filed as extreme weather.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 6 September 2025 | 6 hours 12 minutes | Late-arriving aircraft |
| 21 July 2026 | 4 hours 52 minutes | Extreme weather |
| 11 December 2025 | 4 hours 30 minutes | Security |
| 7 August 2026 | 4 hours 30 minutes | Extreme weather |
| 21 May 2026 | 4 hours 23 minutes | Extreme weather |
Delay causes
Why AS 31 runs late
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 6,915 reported delay minutes.
- 31%National Airspace System
- 26%Carrier
- 22%Late-arriving aircraft
- 17%Extreme weather
- 4%Security
Extreme weather accounts for 17% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.9 times the usual weather exposure. The split is drawn from 6,915 delay minutes reported on AS 31.
Cancellations run at 4.68%, against 1.89% nationally. That is about one flight in twenty 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
9.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 2,422 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
Every one of the 363 flights under AS 31 in the data flew JFK 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. 363 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 31
For a booking, the cancellation rate is the figure to plan around on AS 31: 4.68% of its 363 scheduled flights did not operate. A late arrival costs a little over an hour, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- JFK to SEA, every carrier and departure
- SEA to JFK, the return direction
- Delta Air Lines 699 on the same route73.5%
- Delta Air Lines 740 on the same route68.6%
- Delta Air Lines 688 on the same route64.4%
- Alaska Airlines 21 on the same route69.0%
- Alaska Airlines 23 on the same route78.1%
- Alaska Airlines 17 on the same route50.4%
- John F. Kennedy International (JFK) 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
- What a cancellation rate actually tells you (and what it hides)
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.