Route reliability record
SFO→BOI
San Francisco to Boise
- Flights
- 1,740
- Period
- September 2025 to August 2026
- Distance
- 522 mi
- Carriers
- 2
This route 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 77.3%. The late ones land a little over an hour behind schedule. That rests on 1,740 SFO to BOI flights, with a median arrival 7 minutes early.
Best time to fly SFO to BOI: a 8am–11am departure, ideally on a Saturday. Flights in that window arrived on time 81.7% of the time and Saturday flights 84.2%, against 75.4% for the route overall.
The US average over the same twelve months is 77.3%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
75.4%
Arrivals under 15 minutes late, of 1,733 completed flights
Avg delay
72 min
Across delayed arrivals only, not all flights
Cancelled
0.29%
National rate is 1.89%
Best carrier
SkyWest
75.7% on time across 1,510 flights
These figures cover 1,740 flights between September 2025 and August 2026. Beyond the headline rate, 8.9% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
Which airline is most reliable on SFO to BOI
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 | 1,510 | 75.7% | 75 min | 0.26% | B+ |
| United Airlinesthin sample | 230 | 72.8% | 53 min | 0.43% | C+ |
Flight by flight
Flights on SFO to BOI
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 11 points, against half a point between the best and worst carrier.
- 5am–8am—
- 8am–11am240 flights81.7%
- 11am–2pm287 flights73.3%
- 2pm–5pm406 flights72.8%
- 5pm–8pm537 flights77.7%
- 8pm–5am270 flights71.0%
Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 81.7% of the time, against 71.0% for the overnight window. That is 11 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 537 flights scheduled in it.
Explore
Filter SFO to BOI by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On SFO to BOI, the best departure window is 8am–11am at 81.7% on time and the worst is 8pm–5am at 71.0%, a wide gap of 10.7 points. All US flights leaving 8am–11am ran 83.9%.
- 5–8am—
- 8–11am81.7%
- 11am–2pm73.3%
- 2–5pm72.8%
- 5–8pm77.7%
- 8pm–5am71.0%
best all US flightsScale 60% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 28 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
June is the worst month at 61.4% on time, 28 points below March, the best at 89.3%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. March was the busiest month here, with 178 flights.
Across the week, Saturday is the strongest day at 84.2% on time and Monday the weakest at 67.0%, a spread of 17 points.
Delay causes
Why this route gets delayed
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 31,000 reported delay minutes.
- 41%Late-arriving aircraft
- 34%National Airspace System
- 22%Carrier
- 3%Extreme weather
41% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 31,000 reported delay minutes here, that single category outweighs weather by 12 to one. The split is drawn from 30,800 reported delay minutes.
34% 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 10,000 minutes out of 31,000, against a national NAS share of 21%.
Cancellations are rare at 0.29%, 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 actually costs
8.9% 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 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.
The return leg is a different operation and performs like one: it runs 65.3% on time across 1,744 flights, 10 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 10 points of difference.
The sample behind these figures is 1,740 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.
Work out the risk of missing a connection in BOI after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 89.3% on time and June 61.4%, a swing of 28 points. If the dates move at all, move them out of June before you think about anything else. 1,733 completed flights over 12 months sit behind that.
Common questions
SFO to BOI questions
How often is SFO to BOI delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 24.6% of the 1,740 flights in this analysis, against 22.7% nationally. Delayed flights are late by a little over an hour on average.
How reliable is SFO to BOI compared with the rest of the country?
75.4% of flights arrive on time here against a national 77.3%, a difference of 2 points against it. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on SFO to BOI?
The 8am–11am departure window is the strongest at 81.7% on time. The 8pm–5am window is the weakest at 71.0%, 11 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are June delays on SFO to BOI?
June is the weakest month at 61.4% on time, compared with 89.3% in March. Across the year that is 28 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- BOI to SFO — the return legseparate record
- San Francisco International (SFO) delay statistics
- SkyWest Airlines on SFO to BOI75.7%
- United Airlines on SFO to BOI72.8%
- SFO to LAX, a related route70.9%
- SEA to BOI, a related route86.3%
- SFO to SEA, a related route72.3%
- SkyWest Airlines on-time record75.7%
- United Airlines on-time record72.8%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. SFO to BOI and BOI to SFO are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Embed SFO to BOI’s on-time badge on your site
Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.
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.