Flight number record

AS 4

Alaska Airlines · Seattle to Washington

Route: SEA → DCA
Departs: 08:00
Flights: 365
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s AS 4, check with Alaska Airlines.

AS 4 earns an A. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 55 minutes. That rests on 365 flights, with a median arrival 15 minutes early.

Set against the rest of the country, AS 4's record is 8 points better than the US average of 77.6%. That gap is worth roughly 83 fewer late arrivals for every thousand flights.

On time

85.9%

Arrivals under 15 minutes late, of 354 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

1.10%

National rate is 1.81%

1 hour+ late

4.2%

National rate is 8.1%

These figures cover 365 flights between July 2025 and June 2026. The median arrival is 15 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.

Schedule

When AS 4 flies

AS 4 flies SEA to DCA without a single fixed slot. Its most common scheduled departure was 08:00, used on 222 of 365 flights, with 08:34 (50 flights) and 08:35 (45 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 08:00222 flights60.8%
Departs 08:3450 flights13.7%
Departs 08:3545 flights12.3%

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 08:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and AS 4 runs level with that at 85.9%. 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 4 next to SEA to DCA

Every carrier on SEA to DCA combined arrived on time 81.6% of the time across 1,094 flights, so AS 4 is 4 points ahead of it. Alaska flew 729 flights on the same city pair under all its flight numbers, including this one, and those ran 76.4% on time. Across its whole network Alaska Airlines managed 79.1%, which this flight beats by 7 points.

AS 4 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
AS 4	365	85.9%	53 min	1.10%	A
All Alaska Airlines on SEA–DCA	729	76.4%	58 min	1.10%	B
All carriers on SEA–DCA	1,094	81.6%	68 min	1.74%	B
Alaska Airlines, whole network	293,372	79.1%	52 min	1.28%	B

Across the year

AS 4 quarter by quarter

AS 4 did not run the same all year. Its best quarter was Apr–Jun 2026 at 93.4% on time and its weakest Jul–Sep 2025 at 81.9%, a swing of 12 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 flights81.9%
Oct–Dec 202592 flights84.8%
Jan–Mar 202690 flights83.0%
Apr–Jun 202691 flights93.4%

Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, AS 4 did best on Wednesday at 94.1% on time and worst on Monday at 78.4%. Each day rests on about 52 flights, so a gap of 16 points is worth noticing but could still narrow in another year.

Delay causes

Why AS 4 runs late

One category carries most of the weight here. National Airspace System accounts for 48% of the 2,628 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
48%
Carrier
34%
Extreme weather
16%
Late-arriving aircraft
2%

Extreme weather accounts for 16% 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 2.5 times the usual weather exposure. The split is drawn from 2,628 delay minutes reported on AS 4.

Cancellations sit at 1.10% against a national 1.81%, which is ordinary. Diversions add another 1.92%.

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 2,329 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 365 flights under AS 4 in the data flew SEA to DCA. 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. 365 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 4

For a booking, AS 4 has one of the better records a US domestic flight can show: 85.9% on time and 1.10% cancelled. That is a base rate, not a promise about any single 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