Carrier route record
OOSFO→BOI
SkyWest Airlines · San Francisco to Boise
- Flights
- 1,451
- Period
- July 2025 to June 2026
- Share of route
- 86%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with SkyWest Airlines.
SkyWest on SFO to BOI sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 1,451 flights, with a median arrival 8 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate SkyWest on SFO to BOI from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
75.9%
Arrivals under 15 minutes late, of 1,446 completed flights
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
0.28%
National rate is 1.81%
Whole route
76.5%
Every carrier on SFO to BOI, 1,681 flights
These figures cover 1,451 flights between July 2025 and June 2026. Beyond the headline rate, 8.8% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
SkyWest against every carrier on SFO to BOI
SkyWest flew 1,451 of the 1,681 flights on SFO to BOI, most of the route. Its 75.9% on time is about level with the route as a whole at 76.5%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from United at 79.8% to SkyWest at 75.9%. 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 |
|---|---|---|---|---|---|
| United Airlinesthin sample | 230 | 79.8% | 53 min | 0.43% | B+ |
| SkyWest Airlines (this page) | 1,451 | 75.9% | 73 min | 0.28% | B+ |
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 17 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–8am—
- 8am–11am193 flights87.6%
- 11am–2pm210 flights72.2%
- 2pm–5pm361 flights74.2%
- 5pm–8pm425 flights77.0%
- 8pm–5am262 flights71.0%
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 87.6% of the time, against 71.0% for the overnight window. That is 17 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 425 flights scheduled in it.
Across the year
SkyWest on SFO to BOI through the year
Delays peak in May, when the on-time rate falls to 62.2%. March is the strongest month at 89.3%. Moving a flexible trip across that boundary buys 27 points. March was the busiest month here, with 178 flights.
Across the week, Saturday is the strongest day at 83.4% on time and Monday the weakest at 67.0%. 16 points is a smaller lever than departure hour, but it is free.
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 25,000 reported delay minutes.
- 40%Late-arriving aircraft
- 30%National Airspace System
- 26%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. That is a cascade, and cascades start small and grow through the day. Across 25,000 reported delay minutes here, that single category outweighs weather by 11 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 25,341 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 87.6% on time here.
Cancellations are rare at 0.28%, 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
8.8% 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 a little over an hour, which a normal layover absorbs.
The 522 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 71.1% on time across 1,453 flights, 5 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 5 points of difference.
The sample behind these figures is 1,451 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking SkyWest on SFO to BOI
Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 89.3% on time and May 62.2%, a swing of 27 points. If the dates move at all, move them out of May before you think about anything else. 1,446 completed flights over 12 months sit behind that.
Related
Where to go next
- SFO to BOI, every carrier
- SkyWest on BOI to SFO, the return leg
- United Airlines on SFO to BOI79.8%
- SkyWest Airlines network-wide record
- San Francisco International (SFO) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.