Flight number record

AS 21

Alaska Airlines · New York to Seattle

Route: JFK → SEA
Departs: 07:00
Flights: 358
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s AS 21, check with Alaska Airlines.

AS 21 draws a C−. About one flight in three arrives at least 15 minutes late, and the typical late arrival is roughly 45 minutes behind schedule. Build slack into anything you connect to. That rests on 358 flights, with a median arrival 2 minutes late.

The national on-time rate over the same period is 77.6%, so AS 21 runs 10 points behind the country as a whole. Across a thousand flights that is about 104 extra late arrivals.

On time

67.2%

Arrivals under 15 minutes late, of 345 completed flights

Avg delay

47 min

Across delayed arrivals only, not all flights

Cancelled

3.35%

National rate is 1.81%

1 hour+ late

7.2%

National rate is 8.1%

These figures cover 358 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.

Schedule

When AS 21 flies

AS 21 flies JFK to SEA without a single fixed slot. Its most common scheduled departure was 07:00, used on 263 of 358 flights, with 07:29 (45 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 07:00263 flights73.5%
Departs 07:2945 flights12.6%

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 07:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and AS 21 runs 22 points worse at 67.2%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

AS 21 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 21 is 3 points behind 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 12 points.

AS 21 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
AS 21thin sample	358	67.2%	47 min	3.35%	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 21 quarter by quarter

AS 21 did not run the same all year. Its best quarter was Apr–Jun 2026 at 83.1% on time and its weakest Jan–Mar 2026 at 51.2%, a swing of 32 points on roughly 90 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 flights71.9%
Oct–Dec 202591 flights60.9%
Jan–Mar 202685 flights51.2%
Apr–Jun 202690 flights83.1%

Scale runs 45% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, AS 21 did best on Tuesday at 76.0% on time and worst on Saturday at 62.2%. Each day rests on about 51 flights, so a gap of 14 points is worth noticing but could still narrow in another year.

Delay causes

Why AS 21 runs late

One category carries most of the weight here. National Airspace System accounts for 53% of the 5,318 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

National Airspace System
53%
Carrier
33%
Extreme weather
8%
Late-arriving aircraft
4%
Security
2%

53% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 2,820 minutes out of 5,318, against a national NAS share of 21%. The split is drawn from 5,318 delay minutes reported on AS 21.

Cancellations run at 3.35%, 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

7.2% 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 roughly 45 minutes, 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 358 flights under AS 21 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. 358 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 21

For a booking, the cancellation rate is the figure to plan around on AS 21: 3.35% of its 358 scheduled flights did not operate. A late arrival costs roughly 45 minutes, 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