Carrier route record
OOBOI→SFO
SkyWest Airlines · Boise to San Francisco
- Flights
- 1,513
- Period
- September 2025 to August 2026
- Share of route
- 87%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with SkyWest Airlines.
SkyWest on BOI to SFO draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 1,513 flights, with a median arrival 1 minute early.
The national on-time rate over the same period is 77.3%, so SkyWest on BOI to SFO runs 11 points behind the country as a whole. Across a thousand flights that is about 113 extra late arrivals.
Key figures
On time
66.0%
Arrivals under 15 minutes late, of 1,498 completed flights
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
0.40%
National rate is 1.89%
Whole route
65.3%
Every carrier on BOI to SFO, 1,744 flights
These figures cover 1,513 flights between September 2025 and August 2026. Beyond the headline rate, 13.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
SkyWest against every carrier on BOI to SFO
SkyWest flew 1,513 of the 1,744 flights on BOI to SFO, most of the route. Its 66.0% on time is about level with the route as a whole at 65.3%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from SkyWest at 66.0% to United at 61.3%. 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 |
|---|---|---|---|---|---|
| SkyWest Airlines (this page) | 1,513 | 66.0% | 71 min | 0.40% | C+ |
| United Airlinesthin sample | 231 | 61.3% | 104 min | 0.43% | D+ |
Flight by flight
SkyWest flight numbers on BOI to SFO
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 43 points, against half a point between the best and worst carrier.
- 5am–8am342 flights92.4%
- 8am–11am527 flights56.6%
- 11am–2pm229 flights49.1%
- 2pm–5pm177 flights61.5%
- 5pm–8pm238 flights67.9%
- 8pm–5am—
Scale runs 40% to 100%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 49.1% on time against 92.4% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8am–11am window is the busiest, with 527 flights scheduled in it.
Across the year
SkyWest on BOI to SFO through the year
Delays peak in May, when the on-time rate falls to 45.9%. March is the strongest month at 81.5%. Moving a flexible trip across that boundary buys 36 points. March was the busiest month here, with 178 flights.
Across the week, Saturday is the strongest day at 78.9% on time and Thursday the weakest at 59.7%, a spread of 19 points.
Arrival by arrival
How late SkyWest on BOI to SFO runs when it is late
SkyWest on BOI to SFO often beats the schedule: 421 of 1,498 completed flights, 28%, arrived 15 minutes or more early. The 510 late arrivals split 147 under half an hour, 167 between 30 and 60 minutes, and 196 an hour or more.
- 15+ min early421 flights28.1%
- Within 15 min567 flights37.9%
- 15–29 min late147 flights9.8%
- 30–59 min late167 flights11.1%
- 1–2 hours late132 flights8.8%
- 2+ hours late64 flights4.3%
Scale runs 0% to 100%.
Share of 1,498 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 435 departures that left 15 minutes late or more, only 47 made it up before arrival. In the other direction, 122 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 SFO.
The worst days
Worst days for SkyWest on BOI to SFO
The latest arrival of the period was on 20 February 2026, 15 hours 2 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across February, March, December and January, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 20 February 2026 | 15 hours 2 minutes | Carrier |
| 17 March 2026 | 11 hours 21 minutes | Late-arriving aircraft |
| 21 December 2025 | 10 hours 37 minutes | National Airspace System |
| 3 January 2026 | 10 hours 9 minutes | Carrier |
| 28 December 2025 | 8 hours 17 minutes | Late-arriving aircraft |
Delay causes
Why SkyWest runs late on this route
National Airspace System accounts for 55% of the 36,000 delay minutes carriers reported here, and the remaining four split what is left.
- 55%National Airspace System
- 27%Carrier
- 16%Late-arriving aircraft
- 2%Extreme weather
55% 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 20,000 minutes out of 36,000, against a national NAS share of 21%. The split is drawn from 36,351 reported delay minutes.
Cancellations are rare at 0.40%, 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
13.1% 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.
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.
The return leg is a different operation and performs like one: it runs 75.7% on time across 1,510 flights, 10 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 10 points of difference.
The sample behind these figures is 1,513 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 BOI to SFO
Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 81.5% on time and May 45.9%, a swing of 36 points. If the dates move at all, move them out of May before you think about anything else. 1,498 completed flights over 12 months sit behind that.
Related
Where to go next
- BOI to SFO, every carrier
- SkyWest on SFO to BOI, the return leg
- United Airlines on BOI to SFO61.3%
- SkyWest Airlines network-wide record
- San Francisco International (SFO) delay statistics
- The best time of day to fly, according to 7.05 million flight records
- How often a connection fails at the major US hubs
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.