Route reliability record

PHX→SAN

Phoenix to San Diego

Flights: 5,933
Period: July 2025 to June 2026
Distance: 304 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, 5 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 5,933 flights, of which Frontier Airlines flew 406 at 76.5% on time.

Frontier Airlines is the most reliable of the four carriers covered here at 76.5% on time across 406 flights.

On time

73.1%

Arrivals under 15 minutes late, of 5,843 completed flights

Avg delay

56 min

Across delayed arrivals only, not all flights

Cancelled

1.28%

National rate is 1.81%

Best carrier

Frontier

76.5% on time across 406 flights

These figures cover 5,933 flights between July 2025 and June 2026. The median arrival is 2 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.

Carrier by carrier

Which airline is most reliable on PHX to SAN

The choice of carrier is not cosmetic here. Frontier Airlines arrives on time 76.5% of the time; SkyWest Airlines manages 69.3%. Sample sizes sit next to every figure, because a two-point gap across 446 flights means less than a ten-point one.

On-time performance by carrier on PHX to SAN
Airline	Flights	On time	Avg delay	Cancelled	Grade
Alaska Airlinesthin sample	218	85.4%	56 min	2.29%	A
Frontier Airlines	406	76.5%	83 min	0.99%	B+
American Airlines	1,670	74.5%	64 min	0.72%	C+
Southwest Airlines	3,193	71.7%	50 min	1.03%	C
SkyWest Airlines	446	69.3%	53 min	4.93%	C−

SkyWest Airlines cancels 4.9% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

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 33 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am858 flights90.7%
8am–11am1,147 flights81.3%
11am–2pm895 flights75.1%
2pm–5pm1,234 flights68.8%
5pm–8pm980 flights65.0%
8pm–5am819 flights57.3%

Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 57.3% on time, against 90.7% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 2pm–5pm window is the busiest, with 1,234 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 19 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.

Darker means more delays. Figures are on-time percentages.February best, June worst

June is the worst month at 61.8% on time, 19 points below February, the best at 80.3%. 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. May was the busiest month here, with 554 flights.

Across the week, Saturday is the strongest day at 81.8% on time and Friday the weakest at 66.6%. 15 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 46% 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.

Late-arriving aircraft
46%
Carrier
27%
National Airspace System
23%
Extreme weather
3%
Security
0%

46% 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 17 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 88,162 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 90.7% on time here.

Cancellations sit at 1.28% against a national 1.81%, which is ordinary. Diversions add another 0.24%.

Connections and stage length

What a delay here actually costs

7.3% 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 about an hour kind, which a normal layover absorbs.

At 304 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg runs 75.8% on time across 5,920 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 5,933 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. February runs 80.3% on time and June 61.8%, a swing of 19 points. If the dates move at all, move them out of June before you think about anything else. 5,843 completed flights over 12 months sit behind that.

Common questions

PHX to SAN questions

How often is PHX to SAN 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 26.9% of the 5,933 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

Which airline is most reliable on PHX to SAN?

Frontier Airlines leads at 76.5% on time across 406 flights. SkyWest Airlines is at the other end on 69.3%, a gap of 7 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 PHX to SAN?

The 5am–8am departure window is the strongest at 90.7% on time. The 8pm–5am window is the weakest at 57.3%, 33 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 PHX to SAN?

June is the weakest month at 61.8% on time, compared with 80.3% in February. Across the year that is 19 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Direction matters. PHX to SAN and SAN to PHX 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.

Key figures