Carrier route record
OOBOI→SAN
SkyWest Airlines · Boise to San Diego
- Flights
- 355
- Period
- September 2025 to August 2026
- Share of route
- 34%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with SkyWest Airlines.
SkyWest on BOI to SAN lands a B+, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 355 flights, with a median arrival 2 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate SkyWest on BOI to SAN from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
79.4%
Arrivals under 15 minutes late, of 350 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
0.85%
National rate is 1.89%
Whole route
79.9%
Every carrier on BOI to SAN, 1,033 flights
These figures cover 355 flights between September 2025 and August 2026. The median arrival is 2 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
SkyWest against every carrier on BOI to SAN
SkyWest flew 355 of the 1,033 flights on BOI to SAN, about 34% of it. Its 79.4% on time is about level with the route as a whole at 79.9%. Ranked by on-time rate it is number two 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 Airlinesthin sample | 252 | 90.0% | 33 min | 1.19% | A |
| SkyWest Airlines (this page)thin sample | 355 | 79.4% | 58 min | 0.85% | B+ |
| Southwest Airlines | 426 | 74.4% | 48 min | 0.47% | C+ |
Flight by flight
SkyWest flight numbers on BOI to SAN
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Departure window
When SkyWest 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 355 flights.
- 5am–8am2 flights—
- 8am–11am96 flights84.2%
- 11am–2pm—
- 2pm–5pm—
- 5pm–8pm189 flights76.3%
- 8pm–5am68 flights80.6%
Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.
The early departures do better, though not dramatically: 84.2% on time for the 8am–11am window against 76.3% for 5pm–8pm. Worth taking if the schedule allows, not worth an extra connection. The 5pm–8pm window is the busiest, with 189 flights scheduled in it.
Across the year
SkyWest on BOI to SAN through the year
- Jul–Sep 202530 flights—
- Oct–Dec 202590 flights81.6%
- Jan–Mar 202675 flights80.0%
- Apr–Jun 202698 flights80.6%
- Jul–Sep 202662 flights72.1%
Scale runs 65% to 85%. 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 79.4% on time across 355 flights.
Quarter by quarter SkyWest on BOI to SAN held fairly steady: 81.6% in Oct–Dec 2025, 80.0% in Jan–Mar 2026, 80.6% in Apr–Jun 2026 and 72.1% in Jul–Sep 2026. A spread of 10 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
Across the week, Saturday is the strongest day at 94.1% on time and Friday the weakest at 64.0%, a spread of 30 points.
Arrival by arrival
How late SkyWest on BOI to SAN runs when it is late
The 72 late arrivals split 28 under half an hour, 23 between 30 and 60 minutes, and 21 an hour or more.
- 15+ min early57 flights16.3%
- Within 15 min221 flights63.1%
- 15–29 min late28 flights8.0%
- 30–59 min late23 flights6.6%
- 1–2 hours late12 flights3.4%
- 2+ hours late9 flights2.6%
Scale runs 0% to 100%.
Share of 350 completed flights by arrival against schedule.
10 of 58 late departures made up the time and arrived on time, 17% of them. In the other direction, 24 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 SkyWest on BOI to SAN
The latest arrival of the period was on 18 May 2026, 6 hours 44 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The five worst days are spread across May, January, June and November, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 18 May 2026 | 6 hours 44 minutes | Late-arriving aircraft |
| 2 January 2026 | 3 hours 43 minutes | National Airspace System |
| 4 June 2026 | 2 hours 52 minutes | Carrier |
| 12 January 2026 | 2 hours 37 minutes | Late-arriving aircraft |
| 10 November 2025 | 2 hours 26 minutes | National Airspace System |
Delay causes
Why SkyWest 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 4,183 reported delay minutes.
- 38%Late-arriving aircraft
- 33%National Airspace System
- 24%Carrier
- 5%Extreme weather
38% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 4,183 reported delay minutes here, that single category outweighs weather by 8 to one. The split is drawn from 4,183 reported delay minutes.
33% 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 1,389 minutes out of 4,183, against a national NAS share of 21%.
Cancellations are rare at 0.85%, below the national 1.89% 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
6.0% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.
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 83.9% on time across 356 flights, 5 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 5 points of difference.
One caution: this is a thin sample. 355 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 SkyWest on BOI to SAN
Put together: treat all of this as provisional. 355 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 79.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 350 completed flights over 12 months sit behind that.
Related
Where to go next
- BOI to SAN, every carrier
- SkyWest on SAN to BOI, the return leg
- Alaska Airlines on BOI to SAN90.0%
- Southwest Airlines on BOI to SAN74.4%
- SkyWest Airlines network-wide record
- San Diego International (SAN) delay statistics
- Why the first flight of the morning is statistically safest
- The best day of the week to fly, and why it is the second lever
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.