Route reliability record

DTW→PHX

Detroit to Phoenix

Flights: 2,425
Period: July 2025 to June 2026
Distance: 1,671 mi
Carriers: 5

This route lands a B+, about a point worse than the national rate of 77.6%. About one flight in four arrive 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 2,425 flights, of which 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 this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

76.6%

Arrivals under 15 minutes late, of 2,398 completed flights

Avg delay

80 min

Across delayed arrivals only, not all flights

Cancelled

0.74%

National rate is 1.81%

Best carrier

American

79.7% on time across 628 flights

These figures cover 2,425 flights between July 2025 and June 2026. Beyond the headline rate, 8.6% 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

Which airline is most reliable on DTW to PHX

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 Airlinesthin 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

The best time of day to leave

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 2,425 flights.

5am–8am373 flights80.3%
8am–11am545 flights80.7%
11am–2pm363 flights80.4%
2pm–5pm209 flights73.7%
5pm–8pm444 flights72.2%
8pm–5am491 flights71.8%

Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 80.7% of the time, against 71.8% for the overnight window. That is 9 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 545 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 29 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.

Darker means more delays. Figures are on-time percentages.March best, December worst

December is the weak month at 58.3% on time, against 87.3% in March. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 238 flights.

Across the week, Wednesday is the strongest day at 81.8% on time and Sunday the weakest at 69.4%. 12 points is a smaller lever than departure hour, but it is free.

Delay causes

Why this route gets delayed

One category carries most of the weight here. Carrier accounts for 49% of the 45,000 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
49%
Late-arriving aircraft
33%
National Airspace System
17%
Extreme weather
2%
Security
0%

The largest share of delay minutes, 49%, 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 22,000 of the 45,000 delay minutes reported here. The split is drawn from 44,514 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 80.7% on time here.

Cancellations are rare at 0.74%, 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 actually costs

8.6% 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 are the a little over an hour kind, which a normal layover absorbs.

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 is a different operation and performs like one: it runs 80.7% on time across 2,426 flights, 4 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 4 points of difference.

The sample behind these figures is 2,425 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.

What to do with this

Booking this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 87.3% on time and December 58.3%, a swing of 29 points. If the dates move at all, move them out of December before you think about anything else. 2,398 completed flights over 12 months sit behind that.

Common questions

DTW to PHX questions

How often is DTW to PHX delayed?

About one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.4% of the 2,425 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.

Which airline is most reliable on DTW to PHX?

American Airlines leads at 79.7% on time across 628 flights. Delta Air Lines is at the other end on 74.7%, a gap of 5 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

What time of day has the fewest delays on DTW to PHX?

The 8am–11am departure window is the strongest at 80.7% on time. The 8pm–5am window is the weakest at 71.8%, 9 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.

How bad are December delays on DTW to PHX?

December is the weakest month at 58.3% on time, compared with 87.3% in March. Across the year that is 29 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Direction matters. DTW to PHX and PHX to DTW are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures