Flight number record
OO 4733
SkyWest Airlines · Boise to San Francisco
- Route
- BOI → SFO
- Departs
- 10:35
- Flights
- 337
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4733, 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 4733 draws a D+. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is about an hour behind schedule. Build slack into anything you connect to. That rests on 337 flights, with a median arrival 6 minutes late.
The national on-time rate over the same period is 77.3%, so OO 4733 runs 17 points behind the country as a whole. Across a thousand flights that is about 168 extra late arrivals.
Key figures
On time
60.5%
Arrivals under 15 minutes late, of 337 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.89%
1 hour+ late
9.5%
National rate is 8.3%
These figures cover 337 flights between September 2025 and August 2026. Beyond the headline rate, 9.5% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When OO 4733 flies
OO 4733 flies BOI to SFO without a single fixed slot. Its most common scheduled departure was 10:35, used on 93 of 337 flights, with 12:30 (53 flights) and 10:48 (37 flights) next.
- Departs 10:3593 flights27.6%
- Departs 12:3053 flights15.7%
- Departs 10:4837 flights11.0%
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 10:35 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and OO 4733 runs 23 points worse at 60.5%. 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 4733 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 4733 is 5 points behind 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 trails by 18 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4733thin sample | 337 | 60.5% | 55 min | 0.00% | D+ |
| 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 4733 quarter by quarter
OO 4733 did not run the same all year. Its best quarter was Jan–Mar 2026 at 82.4% on time and its weakest Jul–Sep 2026 at 32.1%, a swing of 50 points on roughly 67 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 flights70.0%
- Oct–Dec 202578 flights75.6%
- Jan–Mar 202685 flights82.4%
- Apr–Jun 202691 flights40.7%
- Jul–Sep 202653 flights32.1%
Scale runs 25% to 90%.
By weekday, OO 4733 did best on Saturday at 78.3% on time and worst on Friday at 49.0%. Each day rests on about 48 flights, so a gap of 29 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 4733 runs when it is late
The 133 late arrivals split 55 under half an hour, 46 between 30 and 60 minutes, and 32 an hour or more.
- 15+ min early71 flights21.1%
- Within 15 min133 flights39.5%
- 15–29 min late55 flights16.3%
- 30–59 min late46 flights13.6%
- 1–2 hours late20 flights5.9%
- 2+ hours late12 flights3.6%
Scale runs 0% to 100%.
Share of 337 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 106 departures that left 15 minutes late or more, only 12 made it up before arrival. In the other direction, 39 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 OO 4733
The latest arrival of the period was on 6 September 2025, 7 hours 15 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 6 September 2025 | 7 hours 15 minutes | Carrier |
| 21 November 2025 | 5 hours 28 minutes | Extreme weather |
| 20 April 2026 | 5 hours 27 minutes | National Airspace System |
| 12 June 2026 | 4 hours 44 minutes | Carrier |
| 17 April 2026 | 4 hours 22 minutes | Carrier |
Delay causes
Why OO 4733 runs late
National Airspace System accounts for 58% of the 7,319 delay minutes carriers reported here, and the remaining four split what is left.
- 58%National Airspace System
- 32%Carrier
- 5%Late-arriving aircraft
- 5%Extreme weather
58% 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 4,231 minutes out of 7,319, against a national NAS share of 21%. The split is drawn from 7,319 delay minutes reported on OO 4733.
Cancellations are rare at 0.00%, below the national 1.89% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.
Connections and routes
What a delay on this flight costs
9.5% 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 same number turns up on one other city pair in the data, including BOI to DEN (19), but none flew often enough under OO 4733 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. 337 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 4733
For a booking, read OO 4733 as 60.5% on time with 0.00% cancelled over 337 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- BOI to SFO, every carrier and departure
- SFO to BOI, the return direction
- SkyWest Airlines 4678 on the same route88.9%
- 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
- How often a connection fails at the major US hubs
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.