Carrier route record
ASIAD→SAN
Alaska Airlines · Washington to San Diego
- 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 IAD to SAN sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 360 flights, with a median arrival 6 minutes early.
The national on-time rate over the same period is 77.6%, so Alaska on IAD to SAN runs 4 points behind the country as a whole. Across a thousand flights that is about 41 extra late arrivals.
Key figures
On time
73.5%
Arrivals under 15 minutes late, of 355 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
0.56%
National rate is 1.81%
Whole route
83.6%
Every carrier on IAD to SAN, 1,400 flights
These figures cover 360 flights between July 2025 and June 2026. The median arrival is 6 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 IAD to SAN
Alaska flew 360 of the 1,400 flights on IAD to SAN, about 26% of it. Its 73.5% on time is 10 points worse than the route as a whole, which runs 83.6%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from United at 87.1% to Alaska at 73.5%.
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 1,040 | 87.1% | 65 min | 0.38% | A+ |
| Alaska Airlines (this page)thin sample | 360 | 73.5% | 48 min | 0.56% | C+ |
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 IAD to SAN record by time of day without the percentages moving on noise. The headline rate of 73.5% is the reliable figure here.
Across the year
Alaska on IAD to SAN through the year
June is the worst month at 53.3% on time, 31 points below May, the best at 83.9%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. January was the busiest month here, with 31 flights.
Across the week, Saturday is the strongest day at 85.7% on time and Friday the weakest at 62.7%. 23 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Alaska runs late on this route
One category carries most of the weight here. National Airspace System accounts for 45% of the 4,542 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.
- 45%National Airspace System
- 34%Late-arriving aircraft
- 12%Extreme weather
- 8%Carrier
- 1%Security
Extreme weather accounts for 12% 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 monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 1.9 times the usual weather exposure. The split is drawn from 4,542 reported delay minutes.
45% 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 2,025 minutes out of 4,542, against a national NAS share of 21%.
Cancellations are rare at 0.56%, 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
5.6% 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 50 minutes, which a normal layover absorbs.
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 87.6% on time across 360 flights, 14 points above 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 IAD to SAN
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 73.5% 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.
Related
Where to go next
- IAD to SAN, every carrier
- Alaska on SAN to IAD, the return leg
- United Airlines on IAD to SAN87.1%
- Alaska Airlines network-wide record
- Washington Dulles International (IAD) delay statistics
- San Diego International (SAN) delay statistics
- Why the first flight of the morning is statistically safest
- Worst months to fly in the US, ranked by the data
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.