Carrier route record

F9PHX→SAN

Frontier Airlines · Phoenix to San Diego

Flights: 406
Period: July 2025 to June 2026
Share of route: 7%
Carriers: 5

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.

Frontier on PHX to SAN lands a B+, about a point worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 406 flights. The strongest carrier on the route with a full sample, American Airlines, flew 1,670 at 74.5% on time.

The US average over the same twelve months is 77.6%, so there is little to separate Frontier on PHX to SAN from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

76.5%

Arrivals under 15 minutes late, of 400 completed flights

Avg delay

83 min

Across delayed arrivals only, not all flights

Cancelled

0.99%

National rate is 1.81%

Whole route

73.1%

Every carrier on PHX to SAN, 5,933 flights

These figures cover 406 flights between July 2025 and June 2026. Beyond the headline rate, 8.5% 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

Frontier against every carrier on PHX to SAN

Frontier flew 406 of the 5,933 flights on PHX to SAN, about 7% of it. Its 76.5% on time is 3 points better than the route as a whole, which runs 73.1%. Ranked by on-time rate it is number two of five carriers on the route, where the range runs from Alaska at 85.4% to SkyWest at 69.3%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The three carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

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 (this page)	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.

Flight by flight

Frontier flight numbers on PHX to SAN

F9 157108:0081.6% · 257 flights

Departure window

When Frontier runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 19 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am64 flights88.7%
8am–11am66 flights78.8%
11am–2pm92 flights77.2%
2pm–5pm114 flights69.4%
5pm–8pm46 flights71.7%
8pm–5am24 flights—

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 88.7% of the time, against 69.4% for the afternoon window. That is 19 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 114 flights scheduled in it.

Across the year

Frontier on PHX to SAN through the year

Darker means more delays. Figures are on-time percentages.October best, May worst

October is the best month on the calendar at 84.8% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. July was the busiest month here, with 48 flights.

Across the week, Tuesday is the strongest day at 91.1% on time and Friday the weakest at 63.6%. 27 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Frontier runs late on this route

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 7,817 reported delay minutes.

Late-arriving aircraft
35%
National Airspace System
27%
Carrier
24%
Extreme weather
14%

Extreme weather accounts for 14% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.2 times the usual weather exposure. The split is drawn from 7,817 reported delay minutes.

35% 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 7,817 reported delay minutes here, that single category outweighs weather by 3 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.

Cancellations sit at 0.99% against a national 1.81%, which is ordinary. Diversions add another 0.49%.

Connections and stage length

What a delay here costs

8.5% 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 last an hour and a half, 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 is a different operation and performs like one: it runs 70.9% on time across 405 flights, 6 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 6 points of difference.

One caution: this is a thin sample. 406 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 Frontier on PHX to SAN

Put together: treat all of this as provisional. 406 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 76.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 400 completed flights over 12 months sit behind that.

Where to go next

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