Carrier route record
ASBOI→SAN
Alaska Airlines · Boise to San Diego
- Flights
- 252
- Period
- September 2025 to August 2026
- Share of route
- 24%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on BOI to SAN 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 13 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 35 minutes. That rests on 252 flights, with a median arrival 8 minutes early.
Set against the rest of the country, Alaska's BOI to SAN record is 13 points better than the US average of 77.3%. That gap is worth roughly 127 fewer late arrivals for every thousand flights.
Key figures
On time
90.0%
Arrivals under 15 minutes late, of 249 completed flights
Avg delay
33 min
Across delayed arrivals only, not all flights
Cancelled
1.19%
National rate is 1.89%
Whole route
79.9%
Every carrier on BOI to SAN, 1,033 flights
These figures cover 252 flights between September 2025 and August 2026. The median arrival is 8 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.
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Carrier by carrier
Alaska against every carrier on BOI to SAN
Alaska flew 252 of the 1,033 flights on BOI to SAN, about 24% of it. Its 90.0% on time is 10 points better than the route as a whole, which runs 79.9%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Alaska at 90.0% to Southwest at 74.4%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 |
|---|---|---|---|---|---|
| Alaska Airlines (this page)thin sample | 252 | 90.0% | 33 min | 1.19% | A |
| SkyWest Airlinesthin sample | 355 | 79.4% | 58 min | 0.85% | B+ |
| Southwest Airlines | 426 | 74.4% | 48 min | 0.47% | C+ |
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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 252 flights.
There are not enough flights in each departure window to split Alaska's BOI to SAN record by time of day without the percentages moving on noise. The headline rate of 90.0% is the reliable figure here.
Across the year
Alaska on BOI to SAN through the year
- Jul–Sep 202530 flights—
- Oct–Dec 202590 flights92.1%
- Jan–Mar 202690 flights86.5%
- Apr–Jun 202642 flights90.5%
Scale runs 80% 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 90.0% on time across 252 flights.
Quarter by quarter Alaska on BOI to SAN held fairly steady: 92.1% in Oct–Dec 2025, 86.5% in Jan–Mar 2026 and 90.5% in Apr–Jun 2026. A spread of 6 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
Across the week, Wednesday is the strongest day at 94.4% on time and Sunday the weakest at 80.0%, a spread of 14 points.
Arrival by arrival
How late Alaska on BOI to SAN runs when it is late
Alaska on BOI to SAN often beats the schedule: 83 of 249 completed flights, 33%, arrived 15 minutes or more early. Most of the lateness is short. 15 of the 25 late arrivals were under half an hour behind, and 3 reached an hour or more.
- 15+ min early83 flights33.3%
- Within 15 min141 flights56.6%
- 15–29 min late15 flights6.0%
- 30–59 min late7 flights2.8%
- 1–2 hours late2 flights0.8%
- 2+ hours late1 flights0.4%
Scale runs 0% to 100%.
Share of 249 completed flights by arrival against schedule.
Only 13 of 249 completed flights left 15 minutes late or more, too few to say how often the time is made up.
The worst days
Worst days for Alaska on BOI to SAN
The latest arrival of the period was on 10 March 2026, 2 hours 41 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in March 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 10 March 2026 | 2 hours 41 minutes | Carrier |
| 2 November 2025 | 1 hour 8 minutes | National Airspace System |
| 30 March 2026 | 1 hour 4 minutes | National Airspace System |
| 7 March 2026 | 54 minutes | Carrier |
| 9 November 2025 | 42 minutes | National Airspace System |
Delay causes
Why Alaska runs late on this route
National Airspace System accounts for 63% of the 834 delay minutes carriers reported here, and the remaining four split what is left.
- 63%National Airspace System
- 36%Carrier
- 1%Extreme weather
The largest share of delay minutes, 36%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 300 of the 834 delay minutes reported here. The split is drawn from 834 reported delay minutes.
63% 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 522 minutes out of 834, against a national NAS share of 21%.
Cancellations sit at 1.19% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 1.2% land an hour or more behind schedule, against 8.3% 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.
The 749 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg is a different operation and performs like one: it runs 81.2% on time across 253 flights, 9 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 9 points of difference.
One caution: this is a thin sample. 252 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 BOI to SAN
Put together: treat all of this as provisional. 252 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 90.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 249 completed flights over 12 months sit behind that.
Related
Where to go next
- BOI to SAN, every carrier
- Alaska on SAN to BOI, the return leg
- SkyWest Airlines on BOI to SAN79.4%
- Southwest Airlines on BOI to SAN74.4%
- Alaska Airlines network-wide record
- San Diego International (SAN) delay statistics
- Late aircraft, weather, or the airline: what actually causes US flight delays
- How to read this site: grades, sample sizes, and honest caveats
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.