Flight number record

OO 4678

SkyWest Airlines · Boise to San Francisco

Route: BOI → SFO
Departs: 07:45
Flights: 277
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 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 10 points better than the national rate of 77.6%. When something does go wrong the average delay runs close to two hours. That rests on 277 flights, with a median arrival 12 minutes early.

Set against the rest of the country, OO 4678's record is 10 points better than the US average of 77.6%. That gap is worth roughly 101 fewer late arrivals for every thousand flights.

On time

87.7%

Arrivals under 15 minutes late, of 276 completed flights

Avg delay

118 min

Across delayed arrivals only, not all flights

Cancelled

0.36%

National rate is 1.81%

1 hour+ late

5.4%

National rate is 8.1%

These figures cover 277 flights between July 2025 and June 2026. The median arrival is 12 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.

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 104 of 277 flights, with 06:30 (41 flights) and 06:15 (31 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 07:45104 flights37.5%
Departs 06:3041 flights14.8%
Departs 06:1531 flights11.2%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

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 87.7%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

OO 4678 next to BOI to SFO

Every carrier on BOI to SFO combined arrived on time 71.2% of the time across 1,684 flights, so OO 4678 is 17 points ahead of it. SkyWest flew 1,453 flights on the same city pair under all its flight numbers, including this one, and those ran 71.1% on time. Across its whole network SkyWest Airlines managed 79.0%, which this flight beats by 9 points.

OO 4678 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 4678thin sample	277	87.7%	118 min	0.36%	A+
All SkyWest Airlines on BOI–SFO	1,453	71.1%	77 min	0.41%	C+
All carriers on BOI–SFO	1,684	71.2%	82 min	0.48%	C+
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	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 Jan–Mar 2026 at 80.9%, a swing of 15 points on roughly 69 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 202543 flights81.4%
Oct–Dec 202554 flights90.7%
Jan–Mar 202689 flights80.9%
Apr–Jun 202691 flights95.6%

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

By weekday, OO 4678 did best on Friday at 100.0% on time and worst on Tuesday at 82.1%. Each day rests on about 40 flights, so a gap of 18 points is worth noticing but could still narrow in another year.

Delay causes

Why OO 4678 runs late

One category carries most of the weight here. Carrier accounts for 70% of the 4,019 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.

Carrier
70%
National Airspace System
16%
Late-arriving aircraft
14%

The largest share of delay minutes, 70%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 2,828 of the 4,019 delay minutes reported here. The split is drawn from 4,019 delay minutes reported on OO 4678.

Cancellations are rare at 0.36%, 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 routes

What a delay on this flight costs

5.4% 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 close to two hours, 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 same number turns up on seven other city pairs in the data, including IAH to BTR (36), IAH to AUS (35) and SFO to FCA (8), 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. 277 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: 87.7% on time and 0.36% cancelled. That is a base rate, not a promise about any single day.

Where to go next

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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures