Flight number record

OO 4643

SkyWest Airlines · Los Angeles to San Diego

Route: LAX → SAN
Departs: 09:17
Flights: 365
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 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 12 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 365 flights, with a median arrival 7 minutes early.

Set against the rest of the country, OO 4643's record is 12 points better than the US average of 77.6%. That gap is worth roughly 118 fewer late arrivals for every thousand flights.

On time

89.4%

Arrivals under 15 minutes late, of 358 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

1.92%

National rate is 1.81%

1 hour+ late

3.1%

National rate is 8.1%

These figures cover 365 flights between July 2025 and June 2026. The median arrival is 7 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 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 365 flights, with 09:07 (63 flights) and 09:00 (47 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 09:17192 flights52.6%
Departs 09:0763 flights17.3%
Departs 09:0047 flights12.9%

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 09:17 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and OO 4643 runs 5 points better at 89.4%. 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 4643 next to LAX to SAN

Every carrier on LAX to SAN combined arrived on time 86.7% of the time across 2,441 flights, so OO 4643 is 3 points ahead of it. SkyWest flew 2,253 flights on the same city pair under all its flight numbers, including this one, and those ran 86.5% on time. Across its whole network SkyWest Airlines managed 79.0%, which this flight beats by 10 points.

OO 4643 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 4643	365	89.4%	63 min	1.92%	A
All SkyWest Airlines on LAX–SAN	2,253	86.5%	65 min	1.02%	A
All carriers on LAX–SAN	2,441	86.7%	64 min	0.94%	A+
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 4643 quarter by quarter

Quarter by quarter OO 4643 held fairly steady: 90.2% in Jul–Sep 2025, 86.0% in Oct–Dec 2025, 86.5% in Jan–Mar 2026 and 94.5% in Apr–Jun 2026. A spread of 9 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights90.2%
Oct–Dec 202592 flights86.0%
Jan–Mar 202690 flights86.5%
Apr–Jun 202691 flights94.5%

Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, OO 4643 ranged from 84.0% on Friday to 94.3% on Tuesday. With about 52 flights behind each day, a spread of 10 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why OO 4643 runs late

One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 2,380 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.

Late-arriving aircraft
43%
Carrier
30%
National Airspace System
26%
Extreme weather
2%

43% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 2,380 reported delay minutes here, that single category outweighs weather by 25 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 2,380 delay minutes reported on OO 4643.

Cancellations sit at 1.92% against a national 1.81%, 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 3.1% land an hour or more behind schedule, against 8.1% 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.

Every one of the 365 flights under OO 4643 in the data flew LAX to SAN. The number was not reused on any other city pair, which makes this a clean record of one route.

One caution: this is a thin sample. 365 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 89.4% on time with 1.92% cancelled over 365 flights. Those are rates from the past twelve months, not a forecast for any particular 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