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DelayAtlas

Carrier route record

F9PHXSFO

Frontier Airlines · Phoenix to San Francisco

Flights
263
Period
July 2025 to June 2026
Share of route
6%
Carriers
6
C+GRADE

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

Frontier on PHX to SFO sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 263 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,444 at 73.1% on time.

United Airlines is the most reliable of the four carriers covered here at 73.1% on time across 1,444 flights.

Key figures

On time

68.6%

Arrivals under 15 minutes late, of 261 completed flights

Avg delay

61 min

Across delayed arrivals only, not all flights

Cancelled

0.76%

National rate is 1.81%

Whole route

67.6%

Every carrier on PHX to SFO, 4,644 flights

These figures cover 263 flights between July 2025 and June 2026. Beyond the headline rate, 10.3% 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 SFO

Frontier flew 263 of the 4,644 flights on PHX to SFO, about 6% of it. Its 68.6% on time is about level with the route as a whole at 67.6%. Ranked by on-time rate it is number three of six carriers on the route, where the range runs from Envoy at 100.0% to Southwest at 60.5%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. United Airlines arrives on time 73.1% of the time; Southwest Airlines manages 60.5%. Sample sizes sit next to every figure, because a two-point gap across 1,079 flights means less than a ten-point one.

On-time performance by carrier on PHX to SFO
AirlineFlightsOn timeAvg delayCancelledGrade
Envoy Airthin sample1100.0%0.00%A+
United Airlines1,44473.1%62 min0.55%C+
Frontier Airlines (this page)thin sample26368.6%61 min0.76%C+
SkyWest Airlines53868.5%65 min0.19%C+
American Airlines1,31966.9%76 min0.91%C+
Southwest Airlines1,07960.5%55 min0.28%D+

The spread between United and Southwest is 13 points, wide enough that it should decide the booking. On a hundred trips that is 13 more arrivals inside the on-time window.

Departure window

When Frontier runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 263 flights.

  • 5am–8am66 flights68.2%
  • 8am–11am21 flights
  • 11am–2pm6 flights
  • 2pm–5pm135 flights71.1%
  • 5pm–8pm35 flights64.7%
  • 8pm–5am

Scale runs 55% to 75%. Rows with fewer than 30 flights show a dash.

The best window here is not the first bank but the 2pm–5pm slot at 71.1% on time, ahead of 5pm–8pm at 64.7%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 2pm–5pm window is the busiest, with 135 flights scheduled in it.

Across the year

Frontier on PHX to SFO through the year

  • Jul–Sep 202557 flights57.9%
  • Oct–Dec 202559 flights77.6%
  • Jan–Mar 202670 flights85.5%
  • Apr–Jun 202677 flights54.5%

Scale runs 45% to 90%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 68.6% on time across 263 flights.

Frontier on PHX to SFO did not run the same all year. Its best quarter was Jan–Mar 2026 at 85.5% on time and its weakest Apr–Jun 2026 at 54.5%, a swing of 31 points on roughly 66 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.

Across the week, Monday is the strongest day at 73.1% on time and Sunday the weakest at 59.3%. 14 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week73.1MonTueWed67.3Thu69.2Fri71.0Sat59.3Sun
Monday: 73.1 percent on time. Tuesday: not enough flights. Wednesday: not enough flights. Thursday: 67.3 percent on time. Friday: 69.2 percent on time. Saturday: 71.0 percent on time. Sunday: 59.3 percent on time

Delay causes

Why Frontier runs late on this route

One category carries most of the weight here. National Airspace System accounts for 52% of the 5,022 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.

  • National Airspace System
    52%
  • Late-arriving aircraft
    33%
  • Carrier
    14%

52% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 2,627 minutes out of 5,022, against a national NAS share of 21%. The split is drawn from 5,022 reported delay minutes.

Cancellations are rare at 0.76%, 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 costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.3% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

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 59.6% on time across 263 flights, 9 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 9 points of difference.

One caution: this is a thin sample. 263 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 SFO

Put together: treat all of this as provisional. 263 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 68.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 261 completed flights over 12 months sit behind that.

Related

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.