Carrier route record

F9DTW→PHX

Frontier Airlines · Detroit to Phoenix

Flights: 310
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 DTW to PHX sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land close to two hours behind schedule. That rests on 310 flights. The strongest carrier on the route with a full sample, American Airlines, flew 628 at 79.7% on time.

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

On time

75.1%

Arrivals under 15 minutes late, of 305 completed flights

Avg delay

112 min

Across delayed arrivals only, not all flights

Cancelled

1.29%

National rate is 1.81%

Whole route

76.6%

Every carrier on DTW to PHX, 2,425 flights

These figures cover 310 flights between July 2025 and June 2026. Beyond the headline rate, 12.5% 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 DTW to PHX

Frontier flew 310 of the 2,425 flights on DTW to PHX, about 13% of it. Its 75.1% on time is 2 points worse than the route as a whole, which runs 76.6%. Ranked by on-time rate it is number four of five carriers on the route, where the range runs from Spirit at 85.8% to Delta at 74.7%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The two 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 DTW to PHX
Airline	Flights	On time	Avg delay	Cancelled	Grade
Spirit Airlinesthin sample	124	85.8%	71 min	1.61%	A
Southwest Airlinesthin sample	30	80.0%	34 min	0.00%	B+
American Airlines	628	79.7%	105 min	0.80%	B+
Frontier Airlines (this page)thin sample	310	75.1%	112 min	1.29%	B
Delta Air Lines	1,333	74.7%	64 min	0.53%	C+

No carrier stands out. American tops the table at 79.7%, 5 points clear of the bottom, which is inside the range this kind of sample moves year to year.

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 22 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am70 flights86.8%
8am–11am68 flights76.1%
11am–2pm33 flights81.8%
2pm–5pm17 flights—
5pm–8pm23 flights—
8pm–5am99 flights64.9%

Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 64.9% on time, against 86.8% 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 99 flights scheduled in it.

Across the year

Frontier on DTW to PHX through the year

Jul–Sep 202568 flights79.1%
Oct–Dec 202563 flights71.0%
Jan–Mar 202688 flights71.8%
Apr–Jun 202691 flights78.0%

Scale runs 65% 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 75.1% on time across 310 flights.

Quarter by quarter Frontier on DTW to PHX held fairly steady: 79.1% in Jul–Sep 2025, 71.0% in Oct–Dec 2025, 71.8% in Jan–Mar 2026 and 78.0% in Apr–Jun 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Friday is the strongest day at 82.2% on time and Monday the weakest at 67.3%. 15 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Frontier runs late on this route

One category carries most of the weight here. Carrier accounts for 48% of the 8,473 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.

Carrier
48%
Late-arriving aircraft
39%
National Airspace System
11%
Extreme weather
2%

39% 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 8,473 reported delay minutes here, that single category outweighs weather by 23 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 8,473 reported delay minutes.

The largest share of delay minutes, 48%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 4,054 of the 8,473 delay minutes reported here.

Cancellations sit at 1.29% 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. 12.5% 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 76.5% on time across 312 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. 310 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 DTW to PHX

Put together: treat all of this as provisional. 310 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 75.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 305 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