Carrier route record

ASSAN→IAD

Alaska Airlines · San Diego to Washington

Flights: 360
Period: July 2025 to June 2026
Share of route: 26%
Carriers: 2

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

Alaska on SAN to IAD earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 10 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 360 flights, with a median arrival 15 minutes early.

Set against the rest of the country, Alaska's SAN to IAD record is 10 points better than the US average of 77.6%. That gap is worth roughly 100 fewer late arrivals for every thousand flights.

On time

87.6%

Arrivals under 15 minutes late, of 355 completed flights

Avg delay

56 min

Across delayed arrivals only, not all flights

Cancelled

0.83%

National rate is 1.81%

Whole route

89.0%

Every carrier on SAN to IAD, 1,400 flights

These figures cover 360 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.

Carrier by carrier

Alaska against every carrier on SAN to IAD

Alaska flew 360 of the 1,400 flights on SAN to IAD, about 26% of it. Its 87.6% on time is about level with the route as a whole at 89.0%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from United at 89.5% to Alaska at 87.6%.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on SAN to IAD
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	1,040	89.5%	87 min	0.48%	A+
Alaska Airlines (this page)thin sample	360	87.6%	56 min	0.83%	A+

Departure window

When Alaska runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 360 flights.

There are not enough flights in each departure window to split Alaska's SAN to IAD record by time of day without the percentages moving on noise. The headline rate of 87.6% is the reliable figure here.

Across the year

Alaska on SAN to IAD through the year

Jul–Sep 202591 flights80.7%
Oct–Dec 202588 flights88.6%
Jan–Mar 202690 flights86.4%
Apr–Jun 202691 flights94.5%

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 87.6% on time across 360 flights.

Alaska on SAN to IAD did not run the same all year. Its best quarter was Apr–Jun 2026 at 94.5% on time and its weakest Jul–Sep 2025 at 80.7%, a swing of 14 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.

Across the week, Tuesday is the strongest day at 92.5% on time and Sunday the weakest at 79.2%. 13 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Alaska runs late on this route

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 2,457 reported delay minutes.

National Airspace System
39%
Late-arriving aircraft
34%
Carrier
20%
Extreme weather
7%

34% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 2,457 reported delay minutes here, that single category outweighs weather by 5 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 2,457 reported delay minutes.

39% 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 959 minutes out of 2,457, against a national NAS share of 21%.

Cancellations are rare at 0.83%, 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 stage length

What a delay here costs

Badly late arrivals are rare here: only 4.5% 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 2,253 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.

The return leg is a different operation and performs like one: it runs 73.5% on time across 360 flights, 14 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 14 points of difference.

One caution: this is a thin sample. 360 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 Alaska on SAN to IAD

Put together: treat all of this as provisional. 360 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 87.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 355 completed flights over 12 months sit behind that.

Where to go next

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