Flight number record

AS 31

Alaska Airlines · New York to Seattle

Route: JFK → SEA
Departs: 16:29
Flights: 363
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 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, 6 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 363 flights, with a median arrival 1 minute early.

The national on-time rate over the same period is 77.6%, so AS 31 runs 6 points behind the country as a whole. Across a thousand flights that is about 63 extra late arrivals.

On time

71.3%

Arrivals under 15 minutes late, of 348 completed flights

Avg delay

73 min

Across delayed arrivals only, not all flights

Cancelled

3.58%

National rate is 1.81%

1 hour+ late

8.9%

National rate is 8.1%

These figures cover 363 flights between July 2025 and June 2026. Beyond the headline rate, 8.9% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

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 93 of 363 flights, with 16:45 (50 flights) and 16:51 (48 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 16:2993 flights25.6%
Departs 16:4550 flights13.8%
Departs 16:5148 flights13.2%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

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 72.4%, and AS 31 runs level with that at 71.3%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

AS 31 next to JFK to SEA

Every carrier on JFK to SEA combined arrived on time 69.7% of the time across 2,906 flights, so AS 31 is 2 points ahead of it. Alaska flew 1,402 flights on the same city pair under all its flight numbers, including this one, and those ran 66.2% on time. Across its whole network Alaska Airlines managed 79.1%, which this flight trails by 8 points.

AS 31 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
AS 31thin sample	363	71.3%	73 min	3.58%	C−
All Alaska Airlines on JFK–SEA	1,402	66.2%	61 min	3.00%	C
All carriers on JFK–SEA	2,906	69.7%	61 min	2.58%	C
Alaska Airlines, whole network	293,372	79.1%	52 min	1.28%	B

Across the year

AS 31 quarter by quarter

AS 31 did not run the same all year. Its best quarter was Apr–Jun 2026 at 85.4% on time and its weakest Jan–Mar 2026 at 62.1%, a swing of 23 points on roughly 91 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 202592 flights74.4%
Oct–Dec 202591 flights62.2%
Jan–Mar 202690 flights62.1%
Apr–Jun 202690 flights85.4%

Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, AS 31 ranged from 66.7% on Wednesday to 78.0% on Saturday. With about 52 flights behind each day, a spread of 11 points is inside normal variation, so the day you fly is not worth changing for this flight.

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 7,263 reported delay minutes.

National Airspace System
34%
Late-arriving aircraft
27%
Carrier
23%
Extreme weather
13%
Security
3%

Extreme weather accounts for 13% 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 2.0 times the usual weather exposure. The split is drawn from 7,263 delay minutes reported on AS 31.

Cancellations run at 3.58%, against 1.81% 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

8.9% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.

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: 3.58% 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.

Where to go next

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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures