Flight number record

OO 6404

SkyWest Airlines · San Francisco to Phoenix

Route: SFO → PHX
Departs: 06:00
Flights: 322
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s OO 6404, 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 6404 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 13 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 322 flights, with a median arrival 9 minutes early.

Set against the rest of the country, OO 6404's record is 13 points better than the US average of 77.6%. That gap is worth roughly 127 fewer late arrivals for every thousand flights.

On time

90.3%

Arrivals under 15 minutes late, of 320 completed flights

Avg delay

60 min

Across delayed arrivals only, not all flights

Cancelled

0.62%

National rate is 1.81%

1 hour+ late

1.6%

National rate is 8.1%

These figures cover 322 flights between July 2025 and June 2026. The median arrival is 9 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 6404 flies

OO 6404 flies SFO to PHX without a single fixed slot. Its most common scheduled departure was 06:00, used on 125 of 322 flights, with 05:50 (50 flights) and 05:40 (40 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 06:00125 flights38.8%
Departs 05:5050 flights15.5%
Departs 05:4040 flights12.4%

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 06:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and OO 6404 runs level with that at 90.3%. 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 6404 next to SFO to PHX

Every carrier on SFO to PHX combined arrived on time 74.4% of the time across 4,643 flights, so OO 6404 is 16 points ahead of it. SkyWest flew 538 flights on the same city pair under all its flight numbers, including this one, and those ran 87.3% on time. Across its whole network SkyWest Airlines managed 79.0%, which this flight beats by 11 points.

OO 6404 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 6404thin sample	322	90.3%	60 min	0.62%	A+
All SkyWest Airlines on SFO–PHX	538	87.3%	67 min	0.74%	A+
All carriers on SFO–PHX	4,643	74.4%	75 min	0.78%	C+
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 6404 quarter by quarter

OO 6404 did not run the same all year. Its best quarter was Oct–Dec 2025 at 95.6% on time and its weakest Apr–Jun 2026 at 80.3%, a swing of 15 points on roughly 81 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 202582 flights92.7%
Oct–Dec 202590 flights95.6%
Jan–Mar 202673 flights91.7%
Apr–Jun 202677 flights80.3%

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

By weekday, OO 6404 ranged from 86.0% on Sunday to 93.5% on Saturday. With about 46 flights behind each day, a spread of 8 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why OO 6404 runs late

One category carries most of the weight here. Carrier accounts for 54% of the 1,852 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
54%
Late-arriving aircraft
28%
National Airspace System
17%
Extreme weather
1%

The largest share of delay minutes, 54%, 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 994 of the 1,852 delay minutes reported here. The split is drawn from 1,852 delay minutes reported on OO 6404.

Cancellations are rare at 0.62%, 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 1.6% 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 651 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 one other city pair in the data, including BFL to PHX (9), but none flew often enough under OO 6404 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SFO to PHX only.

One caution: this is a thin sample. 322 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 6404

For a booking, OO 6404 has one of the better records a US domestic flight can show: 90.3% on time and 0.62% 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