Flight number record

AS 459

Alaska Airlines · Boston to Seattle

Route: BOS → SEA
Departs: 07:20
Flights: 364
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s AS 459, check with Alaska Airlines.

AS 459 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 roughly 40 minutes behind schedule. That rests on 364 flights, with a median arrival 1 minute early.

The national on-time rate over the same period is 77.6%, so AS 459 runs 6 points behind the country as a whole. Across a thousand flights that is about 55 extra late arrivals.

On time

72.1%

Arrivals under 15 minutes late, of 358 completed flights

Avg delay

42 min

Across delayed arrivals only, not all flights

Cancelled

0.82%

National rate is 1.81%

1 hour+ late

4.2%

National rate is 8.1%

These figures cover 364 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 459 flies

AS 459 flies BOS to SEA without a single fixed slot. Its most common scheduled departure was 07:20, used on 145 of 364 flights, with 07:00 (133 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 07:20145 flights39.8%
Departs 07:00133 flights36.5%

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 07:20 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and AS 459 runs 17 points worse at 72.1%. 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 459 next to BOS to SEA

Every carrier on BOS to SEA combined arrived on time 71.4% of the time across 2,461 flights, so AS 459 is about level with it. Alaska flew 1,208 flights on the same city pair under all its flight numbers, including this one, and those ran 70.5% on time. Across its whole network Alaska Airlines managed 79.1%, which this flight trails by 7 points.

AS 459 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
AS 459thin sample	364	72.1%	42 min	0.82%	C+
All Alaska Airlines on BOS–SEA	1,208	70.5%	50 min	1.16%	C
All carriers on BOS–SEA	2,461	71.4%	54 min	1.26%	C
Alaska Airlines, whole network	293,372	79.1%	52 min	1.28%	B

Across the year

AS 459 quarter by quarter

AS 459 did not run the same all year. Its best quarter was Apr–Jun 2026 at 83.5% on time and its weakest Jan–Mar 2026 at 61.6%, a swing of 22 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 flights72.8%
Oct–Dec 202591 flights69.7%
Jan–Mar 202690 flights61.6%
Apr–Jun 202691 flights83.5%

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

By weekday, AS 459 ranged from 67.3% on Tuesday to 75.0% on Monday. With about 52 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.

Delay causes

Why AS 459 runs late

One category carries most of the weight here. National Airspace System accounts for 52% of the 4,203 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
52%
Carrier
27%
Late-arriving aircraft
16%
Extreme weather
5%

52% 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 2,206 minutes out of 4,203, against a national NAS share of 21%. The split is drawn from 4,203 delay minutes reported on AS 459.

Cancellations are rare at 0.82%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 4.2% land an hour or more behind schedule, against 8.1% 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.

At 2,496 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 364 flights under AS 459 in the data flew BOS 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. 364 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 459

For a booking, read AS 459 as 72.1% on time with 0.82% cancelled over 364 flights. Those are rates from the past twelve months, not a forecast for any particular day.

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