Flight number record
OO 4678
SkyWest Airlines · Boise to San Francisco
- Route
- BOI → SFO
- Departs
- 07:45
- Flights
- 326
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4678, check with SkyWest Airlines. SkyWest Airlines flies under contract for larger airlines, so a ticket for this flight may show a different airline code and number.
OO 4678 earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 12 points better than the national rate of 77.3%. When something does go wrong the average delay runs close to two hours. That rests on 326 flights, with a median arrival 13 minutes early.
Set against the rest of the country, OO 4678's record is 12 points better than the US average of 77.3%. That gap is worth roughly 116 fewer late arrivals for every thousand flights.
Key figures
On time
88.9%
Arrivals under 15 minutes late, of 325 completed flights
Avg delay
109 min
Across delayed arrivals only, not all flights
Cancelled
0.31%
National rate is 1.89%
1 hour+ late
4.6%
National rate is 8.3%
These figures cover 326 flights between September 2025 and August 2026. The median arrival is 13 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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Schedule
When OO 4678 flies
OO 4678 flies BOI to SFO without a single fixed slot. Its most common scheduled departure was 07:45, used on 92 of 326 flights, with 06:30 (82 flights) and 06:15 (51 flights) next.
- Departs 07:4592 flights28.2%
- Departs 06:3082 flights25.2%
- Departs 06:1551 flights15.6%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 07:45 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and OO 4678 runs level with that at 88.9%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
OO 4678 next to BOI to SFO
Every carrier on BOI to SFO combined arrived on time 65.3% of the time across 1,744 flights, so OO 4678 is 24 points ahead of it. SkyWest flew 1,513 flights on the same city pair under all its flight numbers, including this one, and those ran 66.0% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 10 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4678thin sample | 326 | 88.9% | 109 min | 0.31% | A+ |
| All SkyWest Airlines on BOI–SFO | 1,513 | 66.0% | 71 min | 0.40% | C+ |
| All carriers on BOI–SFO | 1,744 | 65.3% | 76 min | 0.40% | C+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4678 quarter by quarter
OO 4678 did not run the same all year. Its best quarter was Apr–Jun 2026 at 95.6% on time and its weakest Jul–Sep 2025 at 76.7%, a swing of 19 points on roughly 65 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights76.7%
- Oct–Dec 202554 flights90.7%
- Jan–Mar 202689 flights80.9%
- Apr–Jun 202691 flights95.6%
- Jul–Sep 202662 flights95.2%
Scale runs 70% to 100%.
By weekday, OO 4678 did best on Friday at 100.0% on time and worst on Saturday at 83.0%. Each day rests on about 47 flights, so a gap of 17 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 4678 runs when it is late
OO 4678 often beats the schedule: 153 of 325 completed flights, 47%, arrived 15 minutes or more early. The 36 late arrivals split 13 under half an hour, 8 between 30 and 60 minutes, and 15 an hour or more.
- 15+ min early153 flights47.1%
- Within 15 min136 flights41.8%
- 15–29 min late13 flights4.0%
- 30–59 min late8 flights2.5%
- 1–2 hours late5 flights1.5%
- 2+ hours late10 flights3.1%
Scale runs 0% to 100%.
Share of 325 completed flights by arrival against schedule.
A late pushback is often recovered here: of 33 departures that left 15 minutes late or more, 10 still arrived on time. 13 flights left on time and still arrived late.
The worst days
Worst days for OO 4678
The latest arrival of the period was on 3 January 2026, 10 hours 9 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 3 January 2026 | 10 hours 9 minutes | Carrier |
| 21 May 2026 | 6 hours 46 minutes | Carrier |
| 2 June 2026 | 6 hours 42 minutes | Late-arriving aircraft |
| 21 January 2026 | 4 hours 31 minutes | Carrier |
| 21 February 2026 | 3 hours 53 minutes | Carrier |
Delay causes
Why OO 4678 runs late
Carrier accounts for 69% of the 3,921 delay minutes carriers reported here, and the remaining four split what is left.
- 69%Carrier
- 17%National Airspace System
- 14%Late-arriving aircraft
The largest share of delay minutes, 69%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,710 of the 3,921 delay minutes reported here. The split is drawn from 3,921 delay minutes reported on OO 4678.
Cancellations are rare at 0.31%, 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 routes
What a delay on this flight costs
Badly late arrivals are rare here: only 4.6% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
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 same number turns up on four other city pairs in the data, including IAH to BTR (36), BNA to ORD (1) and FAT to LAX (1), but none flew often enough under OO 4678 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to BOI to SFO only.
One caution: this is a thin sample. 326 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 OO 4678
For a booking, OO 4678 has one of the better records a US domestic flight can show: 88.9% on time and 0.31% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- BOI to SFO, every carrier and departure
- SFO to BOI, the return direction
- SkyWest Airlines 4733 on the same route60.5%
- SkyWest Airlines 3025 on the same route55.6%
- San Francisco International (SFO) delay statistics
- SkyWest Airlines on-time record
- Every SkyWest Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Worst months to fly in the US, ranked by the data
A flight number here means SkyWest Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
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.