Flight number record
OO 4643
SkyWest Airlines · Los Angeles to San Diego
- Route
- LAX → SAN
- Departs
- 09:17
- Flights
- 344
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4643, 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 4643 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 77.3%. When something does go wrong the average delay runs about an hour. That rests on 344 flights, with a median arrival 6 minutes early.
Set against the rest of the country, OO 4643's record is 10 points better than the US average of 77.3%. That gap is worth roughly 102 fewer late arrivals for every thousand flights.
Key figures
On time
87.5%
Arrivals under 15 minutes late, of 337 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
2.03%
National rate is 1.89%
1 hour+ late
3.3%
National rate is 8.3%
These figures cover 344 flights between September 2025 and August 2026. The median arrival is 6 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 4643 flies
OO 4643 flies LAX to SAN without a single fixed slot. Its most common scheduled departure was 09:17, used on 192 of 344 flights, with 09:00 (88 flights) next.
- Departs 09:17192 flights55.8%
- Departs 09:0088 flights25.6%
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 09:17 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and OO 4643 runs 4 points better at 87.5%. 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 4643 next to LAX to SAN
Every carrier on LAX to SAN combined arrived on time 83.2% of the time across 2,452 flights, so OO 4643 is 4 points ahead of it. SkyWest flew 2,162 flights on the same city pair under all its flight numbers, including this one, and those ran 83.9% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 9 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4643thin sample | 344 | 87.5% | 64 min | 2.03% | A |
| All SkyWest Airlines on LAX–SAN | 2,162 | 83.9% | 62 min | 1.06% | B |
| All carriers on LAX–SAN | 2,452 | 83.2% | 60 min | 0.94% | B+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4643 quarter by quarter
OO 4643 did not run the same all year. Its best quarter was Apr–Jun 2026 at 94.5% on time and its weakest Jul–Sep 2026 at 75.6%, a swing of 19 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 202530 flights90.0%
- Oct–Dec 202592 flights86.0%
- Jan–Mar 202690 flights86.5%
- Apr–Jun 202691 flights94.5%
- Jul–Sep 202641 flights75.6%
Scale runs 65% to 100%.
By weekday, OO 4643 did best on Tuesday at 93.9% on time and worst on Sunday at 81.2%. Each day rests on about 49 flights, so a gap of 13 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 4643 runs when it is late
The 42 late arrivals split 17 under half an hour, 14 between 30 and 60 minutes, and 11 an hour or more.
- 15+ min early77 flights22.8%
- Within 15 min218 flights64.7%
- 15–29 min late17 flights5.0%
- 30–59 min late14 flights4.2%
- 1–2 hours late5 flights1.5%
- 2+ hours late6 flights1.8%
Scale runs 0% to 100%.
Share of 337 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 29 departures that left 15 minutes late or more, only 3 made it up before arrival. 16 flights left on time and still arrived late.
The worst days
Worst days for OO 4643
The latest arrival of the period was on 16 March 2026, 5 hours 35 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The five worst days are spread across March, January, July, September and November, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 16 March 2026 | 5 hours 35 minutes | Late-arriving aircraft |
| 5 January 2026 | 5 hours 34 minutes | Late-arriving aircraft |
| 22 July 2026 | 4 hours 50 minutes | Carrier |
| 18 September 2025 | 2 hours 56 minutes | National Airspace System |
| 21 November 2025 | 2 hours 28 minutes | National Airspace System |
Delay causes
Why OO 4643 runs late
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 2,678 reported delay minutes.
- 39%Carrier
- 36%Late-arriving aircraft
- 23%National Airspace System
- 2%Extreme weather
36% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 2,678 reported delay minutes here, that single category outweighs weather by 24 to one. The split is drawn from 2,678 delay minutes reported on OO 4643.
Cancellations sit at 2.03% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 3.3% 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 same number turns up on one other city pair in the data, including BIL to DEN (21), but none flew often enough under OO 4643 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to LAX to SAN only.
One caution: this is a thin sample. 344 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 4643
For a booking, read OO 4643 as 87.5% on time with 2.03% cancelled over 344 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- LAX to SAN, every carrier and departure
- SAN to LAX, the return direction
- SkyWest Airlines 3746 on the same route86.6%
- SkyWest Airlines 4087 on the same route79.5%
- SkyWest Airlines 4001 on the same route79.2%
- SkyWest Airlines 5415 on the same route85.3%
- Los Angeles International (LAX) delay statistics
- San Diego International (SAN) 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
- Why the first flight of the morning is statistically safest
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.