Carrier route record

F9SEA→PHX

Frontier Airlines · Seattle to Phoenix

Flights: 116
Period: September 2025 to August 2026
Share of route: 2%
Carriers: 7

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

Frontier on SEA to PHX 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 77.3%. The late ones land about 2.4 hours behind schedule. That rests on 116 flights. The strongest carrier on the route with a full sample, Envoy Air, flew 760 at 85.3% on time.

Envoy Air is the most reliable of the five carriers covered here at 85.3% on time across 760 flights.

On time

74.5%

Arrivals under 15 minutes late, of 110 completed flights

Avg delay

146 min

Across delayed arrivals only, not all flights

Cancelled

5.17%

National rate is 1.89%

Whole route

78.2%

Every carrier on SEA to PHX, 7,205 flights

These figures cover 116 flights between September 2025 and August 2026. Beyond the headline rate, 10.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally.

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Carrier by carrier

Frontier against every carrier on SEA to PHX

Frontier flew 116 of the 7,205 flights on SEA to PHX, about 2% of it. Its 74.5% on time is 4 points worse than the route as a whole, which runs 78.2%. Ranked by on-time rate it is number six of seven carriers on the route, where the range runs from Envoy at 85.3% to Southwest at 65.1%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. Envoy Air arrives on time 85.3% of the time; Southwest Airlines manages 65.1%. Sample sizes sit next to every figure, because a two-point gap across 1,042 flights means less than a ten-point one.

On-time performance by carrier on SEA to PHX
Airline	Flights	On time	Avg delay	Cancelled	Grade
Envoy Air	760	85.3%	74 min	0.00%	A+
American Airlinesthin sample	221	83.2%	76 min	0.45%	B+
Delta Air Lines	1,768	80.9%	67 min	0.96%	B+
Alaska Airlines	2,889	79.2%	45 min	0.66%	B+
SkyWest Airlines	409	78.5%	80 min	0.49%	B+
Frontier Airlines (this page)thin sample	116	74.5%	146 min	5.17%	C−
Southwest Airlines	1,042	65.1%	49 min	0.77%	C+

The spread between Envoy and Southwest is 20 points, wide enough that it should decide the booking. On a hundred trips that is 20 more arrivals inside the on-time window.

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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 116 flights.

There are not enough flights in each departure window to split Frontier's SEA to PHX record by time of day without the percentages moving on noise. The headline rate of 74.5% is the reliable figure here.

Across the year

Frontier on SEA to PHX through the year

Jul–Sep 202517 flights—
Oct–Dec 202542 flights62.5%
Jan–Mar 202647 flights77.8%
Apr–Jun 202610 flights—

Scale runs 55% to 85%. 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 74.5% on time across 116 flights.

Split by quarter, Frontier on SEA to PHX logged 17 flights in Jul–Sep 2025, 42 flights in Oct–Dec 2025, 47 flights in Jan–Mar 2026 and 10 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 74.5% annual figure is the one to use.

Arrival by arrival

How late Frontier on SEA to PHX runs when it is late

Frontier on SEA to PHX often beats the schedule: 34 of 110 completed flights, 31%, arrived 15 minutes or more early. The 28 late arrivals split 11 under half an hour, 6 between 30 and 60 minutes, and 11 an hour or more.

15+ min early34 flights30.9%
Within 15 min48 flights43.6%
15–29 min late11 flights10.0%
30–59 min late6 flights5.5%
1–2 hours late5 flights4.5%
2+ hours late6 flights5.5%

Scale runs 0% to 100%.

Share of 110 completed flights by arrival against schedule.

7 of 28 late departures made up the time and arrived on time, 25% of them. In the other direction, 7 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at PHX.

The worst days

Worst days for Frontier on SEA to PHX

The latest arrival of the period was on 19 December 2025, 23 hours 1 minute behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on three of the five worst days.

The latest arrivals of Frontier on SEA to PHX in the period
Date	Arrived late by	Largest filed cause
19 December 2025	23 hours 1 minute	Late-arriving aircraft
13 February 2026	21 hours 14 minutes	Carrier
20 December 2025	2 hours 33 minutes	Late-arriving aircraft
10 October 2025	2 hours 31 minutes	Late-arriving aircraft
12 April 2026	2 hours 14 minutes	Carrier

Delay causes

Why Frontier runs late on this route

Late-arriving aircraft accounts for 51% of the 4,097 delay minutes carriers reported here, and the remaining four split what is left.

Late-arriving aircraft
51%
Carrier
44%
National Airspace System
5%
Extreme weather
0%

51% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 4,097 reported delay minutes here, that single category outweighs weather by 51 to one. The split is drawn from 4,097 reported delay minutes.

The largest share of delay minutes, 44%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,804 of the 4,097 delay minutes reported here.

Cancellations run at 5.17%, against 1.89% nationally. That is about one flight in twenty cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and stage length

What a delay here costs

10.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.

The 1,107 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 return leg is a different operation and performs like one: it runs 83.6% on time across 116 flights, 9 points above 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. 116 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 SEA to PHX

Put together: the delay figures matter less here than the 5.17% cancellation rate. A late arrival costs you about 2.4 hours; a cancelled flight costs you the day. Book the 8pm–5am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 110 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures