Flight number record
OO 6404
SkyWest Airlines · San Francisco to Phoenix
- Route
- SFO → PHX
- Departs
- 06:00
- Flights
- 324
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 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 77.3%. When something does go wrong the average delay runs about an hour. That rests on 324 flights, with a median arrival 10 minutes early.
Set against the rest of the country, OO 6404's record is 13 points better than the US average of 77.3%. That gap is worth roughly 134 fewer late arrivals for every thousand flights.
Key figures
On time
90.7%
Arrivals under 15 minutes late, of 322 completed flights
Avg delay
67 min
Across delayed arrivals only, not all flights
Cancelled
0.62%
National rate is 1.89%
1 hour+ late
1.9%
National rate is 8.3%
These figures cover 324 flights between September 2025 and August 2026. The median arrival is 10 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.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 90 of 324 flights, with 05:50 (60 flights) and 05:40 (41 flights) next.
- Departs 06:0090 flights27.8%
- Departs 05:5060 flights18.5%
- Departs 05:4041 flights12.7%
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 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 90.7%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Against the route
OO 6404 next to SFO to PHX
Every carrier on SFO to PHX combined arrived on time 72.8% of the time across 4,727 flights, so OO 6404 is 18 points ahead of it. SkyWest flew 572 flights on the same city pair under all its flight numbers, including this one, and those ran 85.2% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 12 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 6404thin sample | 324 | 90.7% | 67 min | 0.62% | A+ |
| All SkyWest Airlines on SFO–PHX | 572 | 85.2% | 75 min | 0.70% | A+ |
| All carriers on SFO–PHX | 4,727 | 72.8% | 74 min | 0.72% | C+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 6404 quarter by quarter
OO 6404 did not run the same all year. Its best quarter was Jul–Sep 2026 at 96.8% on time and its weakest Apr–Jun 2026 at 80.3%, a swing of 17 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 202522 flights—
- Oct–Dec 202590 flights95.6%
- Jan–Mar 202673 flights91.7%
- Apr–Jun 202677 flights80.3%
- Jul–Sep 202662 flights96.8%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, OO 6404 ranged from 86.4% on Sunday to 93.5% on Saturday. With about 46 flights behind each day, a spread of 7 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late OO 6404 runs when it is late
OO 6404 often beats the schedule: 108 of 322 completed flights, 34%, arrived 15 minutes or more early. Most of the lateness is short. 17 of the 30 late arrivals were under half an hour behind, and 6 reached an hour or more.
- 15+ min early108 flights33.5%
- Within 15 min184 flights57.1%
- 15–29 min late17 flights5.3%
- 30–59 min late7 flights2.2%
- 1–2 hours late3 flights0.9%
- 2+ hours late3 flights0.9%
Scale runs 0% to 100%.
Share of 322 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 25 departures that left 15 minutes late or more, only 2 made it up before arrival. 7 flights left on time and still arrived late.
The worst days
Worst days for OO 6404
The latest arrival of the period was on 25 May 2026, 12 hours 10 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On three of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 25 May 2026 | 12 hours 10 minutes | Carrier |
| 14 July 2026 | 3 hours 49 minutes | Late-arriving aircraft |
| 7 March 2026 | 2 hours 40 minutes | Late-arriving aircraft |
| 10 November 2025 | 1 hour 51 minutes | National Airspace System |
| 23 April 2026 | 1 hour 21 minutes | Late-arriving aircraft |
Delay causes
Why OO 6404 runs late
Carrier accounts for 46% of the 2,019 delay minutes carriers reported here, and the remaining four split what is left.
- 46%Carrier
- 36%Late-arriving aircraft
- 17%National Airspace System
- 1%Extreme weather
36% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 2,019 reported delay minutes here, that single category outweighs weather by 36 to one. The split is drawn from 2,019 delay minutes reported on OO 6404.
Cancellations are rare at 0.62%, below the national 1.89% 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 1.9% 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 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.
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. 324 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: 90.7% on time and 0.62% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- SFO to PHX, every carrier and departure
- PHX to SFO, the return direction
- United Airlines 2374 on the same route90.8%
- San Francisco International (SFO) delay statistics
- Phoenix Sky Harbor International (PHX) 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.