Flight number record

OO 4001

SkyWest Airlines · Los Angeles to San Diego

Route: LAX → SAN
Departs: 14:30
Flights: 270
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s OO 4001, 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 4001 earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 55 minutes. That rests on 270 flights, with a median arrival 3 minutes early.

Set against the rest of the country, OO 4001's record is 7 points better than the US average of 77.6%. That gap is worth roughly 72 fewer late arrivals for every thousand flights.

On time

84.8%

Arrivals under 15 minutes late, of 269 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

0.37%

National rate is 1.81%

1 hour+ late

3.7%

National rate is 8.1%

These figures cover 270 flights between July 2025 and June 2026. The median arrival is 3 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 4001 flies

OO 4001 flies LAX to SAN without a single fixed slot. Its most common scheduled departure was 14:30, used on 56 of 270 flights, with 14:25 (42 flights) and 14:02 (36 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 14:3056 flights20.7%
Departs 14:2542 flights15.6%
Departs 14:0236 flights13.3%

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 14:30 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and OO 4001 runs 12 points better at 84.8%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

OO 4001 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 4001 is 2 points behind 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 6 points.

OO 4001 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 4001thin sample	270	84.8%	53 min	0.37%	B+
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 4001 quarter by quarter

OO 4001 did not run the same all year. Its best quarter was Apr–Jun 2026 at 91.7% on time and its weakest Oct–Dec 2025 at 78.8%, a swing of 13 points on roughly 68 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 202560 flights86.7%
Oct–Dec 202567 flights78.8%
Jan–Mar 202683 flights83.1%
Apr–Jun 202660 flights91.7%

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, OO 4001 did best on Tuesday at 93.0% on time and worst on Monday at 74.4%. Each day rests on about 39 flights, so a gap of 19 points is worth noticing but could still narrow in another year.

Delay causes

Why OO 4001 runs late

One category carries most of the weight here. Carrier accounts for 73% of the 2,189 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
73%
National Airspace System
21%
Extreme weather
7%

The largest share of delay minutes, 73%, 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 1,597 of the 2,189 delay minutes reported here. The split is drawn from 2,189 delay minutes reported on OO 4001.

Cancellations are rare at 0.37%, 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

Badly late arrivals are rare here: only 3.7% 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.

The same number turns up on three other city pairs in the data, including SAN to LAX (138), PDX to SEA (16) and SEA to PDX (16), but none flew often enough under OO 4001 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. 270 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 4001

For a booking, read OO 4001 as 84.8% on time with 0.37% cancelled over 270 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