Carrier route record

F9PHX→DTW

Frontier Airlines · Phoenix to Detroit

Flights: 312
Period: July 2025 to June 2026
Share of route: 13%
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 DTW 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 312 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 1,331 at 84.3% on time.

The US average over the same twelve months is 77.6%, so there is little to separate Frontier on PHX to DTW 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 307 completed flights

Avg delay

85 min

Across delayed arrivals only, not all flights

Cancelled

1.28%

National rate is 1.81%

Whole route

80.7%

Every carrier on PHX to DTW, 2,426 flights

These figures cover 312 flights between July 2025 and June 2026. Beyond the headline rate, 9.4% 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 DTW

Frontier flew 312 of the 2,426 flights on PHX to DTW, about 13% of it. Its 76.5% on time is 4 points worse than the route as a whole, which runs 80.7%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from Delta at 84.3% to Southwest at 56.7%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 84.3% of the time; American Airlines manages 76.2%. Sample sizes sit next to every figure, because a two-point gap across 628 flights means less than a ten-point one.

On-time performance by carrier on PHX to DTW
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	1,331	84.3%	82 min	0.68%	B+
Spirit Airlinesthin sample	125	80.5%	114 min	1.60%	B
Frontier Airlines (this page)thin sample	312	76.5%	85 min	1.28%	B
American Airlines	628	76.2%	76 min	0.64%	B+
Southwest Airlinesthin sample	30	56.7%	38 min	0.00%	D+

Delta leads American by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

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 27 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am46 flights89.1%
8am–11am9 flights—
11am–2pm29 flights—
2pm–5pm47 flights84.4%
5pm–8pm75 flights62.2%
8pm–5am106 flights74.0%

Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 62.2% on time, against 89.1% 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 8pm–5am window is the busiest, with 106 flights scheduled in it.

Across the year

Frontier on PHX to DTW through the year

Jul–Sep 202567 flights72.7%
Oct–Dec 202564 flights85.7%
Jan–Mar 202690 flights73.9%
Apr–Jun 202691 flights75.6%

Scale runs 65% 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 76.5% on time across 312 flights.

Frontier on PHX to DTW did not run the same all year. Its best quarter was Oct–Dec 2025 at 85.7% on time and its weakest Jul–Sep 2025 at 72.7%, a swing of 13 points on roughly 78 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, Thursday is the strongest day at 83.0% on time and Friday the weakest at 69.4%. 14 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 6,099 reported delay minutes.

Carrier
38%
Late-arriving aircraft
35%
Extreme weather
16%
National Airspace System
10%

Extreme weather accounts for 16% 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 2.6 times the usual weather exposure. The split is drawn from 6,099 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 6,099 reported delay minutes here, that single category outweighs weather by 2 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 1.28% against a national 1.81%, which is ordinary. Diversions add another 0.32%.

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. 9.4% 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.

At 1,671 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The return leg runs 75.1% on time across 310 flights, within about a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 312 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 DTW

Put together: treat all of this as provisional. 312 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. 307 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