Flight number record
AS 389
Alaska Airlines · Boston to San Diego
- Route
- BOS → SAN
- Departs
- 16:33
- Flights
- 314
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AS 389, check with Alaska Airlines.
AS 389 sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 8 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 314 flights, with a median arrival 3 minutes early.
The national on-time rate over the same period is 77.3%, so AS 389 runs 8 points behind the country as a whole. Across a thousand flights that is about 78 extra late arrivals.
Key figures
On time
69.5%
Arrivals under 15 minutes late, of 308 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
1.27%
National rate is 1.89%
1 hour+ late
9.1%
National rate is 8.3%
These figures cover 314 flights between September 2025 and August 2026. Beyond the headline rate, 9.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When AS 389 flies
AS 389 flies BOS to SAN without a single fixed slot. Its most common scheduled departure was 16:33, used on 69 of 314 flights, with 16:24 (41 flights) and 17:40 (35 flights) next.
- Departs 16:3369 flights22.0%
- Departs 16:2441 flights13.1%
- Departs 17:4035 flights11.1%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 16:33 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and AS 389 runs 2 points worse at 69.5%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
AS 389 next to BOS to SAN
Every carrier on BOS to SAN combined arrived on time 75.3% of the time across 1,880 flights, so AS 389 is 6 points behind it. Alaska flew 508 flights on the same city pair under all its flight numbers, including this one, and those ran 74.6% on time. Across its whole network Alaska Airlines managed 79.7%, which this flight trails by 10 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 389thin sample | 314 | 69.5% | 58 min | 1.27% | C |
| All Alaska Airlines on BOS–SAN | 508 | 74.6% | 71 min | 1.57% | C |
| All carriers on BOS–SAN | 1,880 | 75.3% | 62 min | 1.81% | B |
| Alaska Airlines, whole network | 309,844 | 79.7% | 52 min | 1.20% | B |
Across the year
AS 389 quarter by quarter
Quarter by quarter AS 389 held fairly steady: 71.4% in Oct–Dec 2025, 71.6% in Jan–Mar 2026, 65.9% in Apr–Jun 2026 and 73.2% in Jul–Sep 2026. A spread of 7 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202517 flights—
- Oct–Dec 202566 flights71.4%
- Jan–Mar 202684 flights71.6%
- Apr–Jun 202691 flights65.9%
- Jul–Sep 202656 flights73.2%
Scale runs 55% to 80%. Rows with fewer than 30 flights show a dash.
By weekday, AS 389 did best on Tuesday at 76.2% on time and worst on Friday at 63.3%. Each day rests on about 45 flights, so a gap of 13 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late AS 389 runs when it is late
AS 389 often beats the schedule: 97 of 308 completed flights, 31%, arrived 15 minutes or more early. The 94 late arrivals split 32 under half an hour, 34 between 30 and 60 minutes, and 28 an hour or more.
- 15+ min early97 flights31.5%
- Within 15 min117 flights38.0%
- 15–29 min late32 flights10.4%
- 30–59 min late34 flights11.0%
- 1–2 hours late21 flights6.8%
- 2+ hours late7 flights2.3%
Scale runs 0% to 100%.
Share of 308 completed flights by arrival against schedule.
A late pushback is often recovered here: of 80 departures that left 15 minutes late or more, 25 still arrived on time. In the other direction, 39 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at SAN.
The worst days
Worst days for AS 389
The latest arrival of the period was on 13 October 2025, 6 hours 52 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 13 October 2025 | 6 hours 52 minutes | Late-arriving aircraft |
| 13 March 2026 | 5 hours 47 minutes | Late-arriving aircraft |
| 21 September 2025 | 5 hours 8 minutes | Carrier |
| 30 July 2026 | 2 hours 28 minutes | Late-arriving aircraft |
| 3 March 2026 | 2 hours 23 minutes | Carrier |
Delay causes
Why AS 389 runs late
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 5,405 reported delay minutes.
- 40%Late-arriving aircraft
- 37%National Airspace System
- 19%Carrier
- 4%Extreme weather
40% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 5,405 reported delay minutes here, that single category outweighs weather by 9 to one. The split is drawn from 5,405 delay minutes reported on AS 389.
Cancellations sit at 1.27% against a national 1.89%, which is ordinary. Diversions add another 0.64%.
Connections and routes
What a delay on this flight costs
9.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 2,588 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 314 flights under AS 389 in the data flew BOS to SAN. 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. 314 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 389
For a booking, AS 389 is one of the weaker ways to fly BOS to SAN: 6 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.
Related
Where to go next
- BOS to SAN, every carrier and departure
- SAN to BOS, the return direction
- Delta Air Lines 571 on the same route66.0%
- JetBlue Airways 619 on the same route87.2%
- Boston Logan International (BOS) delay statistics
- San Diego International (SAN) delay statistics
- Alaska Airlines on-time record
- Every Alaska Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.