Carrier route record

OOBOI→SAN

SkyWest Airlines · Boise to San Diego

Flights: 404
Period: July 2025 to June 2026
Share of route: 39%
Carriers: 3

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

SkyWest on BOI to SAN lands a B+, 5 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 404 flights, with a median arrival 4 minutes early.

Set against the rest of the country, SkyWest's BOI to SAN record is 5 points better than the US average of 77.6%. That gap is worth roughly 46 fewer late arrivals for every thousand flights.

On time

82.2%

Arrivals under 15 minutes late, of 400 completed flights

Avg delay

60 min

Across delayed arrivals only, not all flights

Cancelled

0.50%

National rate is 1.81%

Whole route

82.1%

Every carrier on BOI to SAN, 1,039 flights

These figures cover 404 flights between July 2025 and June 2026. The median arrival is 4 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

SkyWest against every carrier on BOI to SAN

SkyWest flew 404 of the 1,039 flights on BOI to SAN, about 39% of it. Its 82.2% on time is about level with the route as a whole at 82.1%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Alaska at 89.2% to Southwest at 77.0%. 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.

On-time performance by carrier on BOI to SAN
Airline	Flights	On time	Avg delay	Cancelled	Grade
Alaska Airlinesthin sample	263	89.2%	34 min	1.14%	A
SkyWest Airlines (this page)	404	82.2%	60 min	0.50%	B+
Southwest Airlines	372	77.0%	46 min	0.27%	B+

Flight by flight

SkyWest flight numbers on BOI to SAN

OO 348119:5578.4% · 305 flights

Departure window

When SkyWest runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 16 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1 flights—
8am–11am98 flights93.9%
11am–2pm—
2pm–5pm—
5pm–8pm176 flights78.6%
8pm–5am129 flights78.1%

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

Book the morning departure. Flights leaving between 8am–11am arrive on time 93.9% of the time, against 78.1% for the overnight window. That is 16 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 176 flights scheduled in it.

Across the year

SkyWest on BOI to SAN through the year

Jul–Sep 2025141 flights85.0%
Oct–Dec 202590 flights81.6%
Jan–Mar 202675 flights80.0%
Apr–Jun 202698 flights80.6%

Scale runs 70% to 90%. 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 82.2% on time across 404 flights.

Quarter by quarter SkyWest on BOI to SAN held fairly steady: 85.0% in Jul–Sep 2025, 81.6% in Oct–Dec 2025, 80.0% in Jan–Mar 2026 and 80.6% in Apr–Jun 2026. A spread of 5 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 92.9% on time and Friday the weakest at 73.2%. 20 points is a smaller lever than departure hour, but it is free.

Delay causes

Why SkyWest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 4,232 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.

Late-arriving aircraft
43%
National Airspace System
29%
Carrier
23%
Extreme weather
5%

43% 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 4,232 reported delay minutes here, that single category outweighs weather by 9 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 4,232 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 93.9% on time here.

Cancellations are rare at 0.50%, 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

5.2% 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 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The return leg is a different operation and performs like one: it runs 86.9% on time across 405 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. 404 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. 404 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 82.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 400 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