Route reliability record
SFO→PHX
San Francisco to Phoenix
- Flights
- 4,643
- Period
- July 2025 to June 2026
- Distance
- 651 mi
- Carriers
- 5
This route sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 4,643 flights, of which SkyWest Airlines flew 538 at 87.3% on time.
SkyWest Airlines is the most reliable of the four carriers covered here at 87.3% on time across 538 flights.
Key figures
On time
74.4%
Arrivals under 15 minutes late, of 4,598 completed flights
Avg delay
75 min
Across delayed arrivals only, not all flights
Cancelled
0.78%
National rate is 1.81%
Best carrier
SkyWest
87.3% on time across 538 flights
These figures cover 4,643 flights between July 2025 and June 2026. Beyond the headline rate, 8.8% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on SFO to PHX
The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 87.3% of the time; Southwest Airlines manages 61.1%. Sample sizes sit next to every figure, because a two-point gap across 1,079 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 538 | 87.3% | 67 min | 0.74% | A+ |
| United Airlines | 1,443 | 81.0% | 59 min | 0.49% | B+ |
| American Airlines | 1,320 | 75.7% | 106 min | 0.83% | B+ |
| Southwest Airlines | 1,079 | 61.1% | 57 min | 0.56% | D+ |
| Frontier Airlinesthin sample | 263 | 59.6% | 98 min | 3.04% | D− |
The spread between SkyWest and Southwest is 26 points, wide enough that it should decide the booking. On a hundred trips that is 26 more arrivals inside the on-time window.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 points, against 26 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am828 flights93.8%
- 8am–11am827 flights78.3%
- 11am–2pm932 flights67.5%
- 2pm–5pm953 flights66.8%
- 5pm–8pm695 flights70.2%
- 8pm–5am408 flights67.6%
Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 93.8% of the time, against 66.8% for the afternoon window. That is 27 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 953 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 20 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
June is the worst month at 64.5% on time, 20 points below March, the best at 84.1%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. March was the busiest month here, with 452 flights.
Across the week, Saturday is the strongest day at 80.9% on time and Monday the weakest at 68.4%. 13 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 55% of the 88,000 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.
- 55%Late-arriving aircraft
- 34%Carrier
- 10%National Airspace System
- 1%Extreme weather
- 0%Security
55% 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 88,000 reported delay minutes here, that single category outweighs weather by 55 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 87,800 reported delay minutes.
The largest share of delay minutes, 34%, 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 30,000 of the 88,000 delay minutes reported here.
Cancellations are rare at 0.78%, 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 stage length
What a delay here actually costs
8.8% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route are the a little over an hour kind, which a normal layover absorbs.
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 return leg is a different operation and performs like one: it runs 67.6% on time across 4,644 flights, 7 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 7 points of difference.
The sample behind these figures is 4,643 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 84.1% on time and June 64.5%, a swing of 20 points. If the dates move at all, move them out of June before you think about anything else. 4,598 completed flights over 12 months sit behind that.
Common questions
SFO to PHX questions
How often is SFO to PHX delayed?
About one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 25.6% of the 4,643 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on SFO to PHX?
SkyWest Airlines leads at 87.3% on time across 538 flights. Southwest Airlines is at the other end on 61.1%, a gap of 26 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on SFO to PHX?
The 5am–8am departure window is the strongest at 93.8% on time. The 2pm–5pm window is the weakest at 66.8%, 27 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are June delays on SFO to PHX?
June is the weakest month at 64.5% on time, compared with 84.1% in March. Across the year that is 20 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- PHX to SFO — the return legseparate record
- San Francisco International (SFO) delay statistics
- Phoenix Sky Harbor International (PHX) delay statistics
- SkyWest Airlines on-time record87.3%
- United Airlines on-time record81.0%
- American Airlines on-time record75.7%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. SFO to PHX and PHX to SFO are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.