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DelayAtlas

Carrier route record

DLMIADTW

Delta Air Lines · Miami to Detroit

Flights
966
Period
July 2025 to June 2026
Share of route
53%
Carriers
6
B+GRADE

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

Delta on MIA to DTW lands a B+, level with the national rate of 77.6%. Roughly 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 966 flights, with a median arrival 7 minutes early.

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

Key figures

On time

77.7%

Arrivals under 15 minutes late, of 955 completed flights

Avg delay

88 min

Across delayed arrivals only, not all flights

Cancelled

0.93%

National rate is 1.81%

Whole route

72.9%

Every carrier on MIA to DTW, 1,813 flights

These figures cover 966 flights between July 2025 and June 2026. The median arrival is 7 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

Carrier by carrier

Delta against every carrier on MIA to DTW

Delta flew 966 of the 1,813 flights on MIA to DTW, most of the route. Its 77.7% on time is 5 points better than the route as a whole, which runs 72.9%. Ranked by on-time rate it is number two of six carriers on the route, where the range runs from Envoy at 82.8% to Republic at 60.0%. Four of those carriers flew fewer than 365 flights here, so treat their positions as rough.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on MIA to DTW
AirlineFlightsOn timeAvg delayCancelledGrade
Envoy Airthin sample8782.8%46 min0.00%B+
Delta Air Lines (this page)96677.7%88 min0.93%B+
American Airlines39468.3%66 min1.27%C
Frontier Airlinesthin sample6467.7%88 min3.12%C−
Spirit Airlinesthin sample29261.7%71 min3.42%D−
Republic Airwaysthin sample1060.0%162 min0.00%D+

Flight by flight

Delta flight numbers on MIA to DTW

Departure window

When Delta runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 25 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am
  • 8am–11am311 flights90.0%
  • 11am–2pm364 flights77.2%
  • 2pm–5pm
  • 5pm–8pm291 flights64.9%
  • 8pm–5am

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

The 5pm–8pm window is where this operation falls apart: 64.9% on time, against 90.0% for the 8am–11am 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 11am–2pm window is the busiest, with 364 flights scheduled in it.

Across the year

Delta on MIA to DTW through the year

On-time rate by calendar month77J80F72M83A75M75J79J81A90S88O74N63D
Darker means more delays. Figures are on-time percentages.September best, December worst

December is the weak month at 62.9% on time, against 90.0% in September. 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. January was the busiest month here, with 93 flights.

Across the week, Wednesday is the strongest day at 83.2% on time and Sunday the weakest at 73.0%. 10 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week77.0Mon81.4Tue83.2Wed80.1Thu74.3Fri74.6Sat73.0Sun
Monday: 77.0 percent on time. Tuesday: 81.4 percent on time. Wednesday: 83.2 percent on time. Thursday: 80.1 percent on time. Friday: 74.3 percent on time. Saturday: 74.6 percent on time. Sunday: 73.0 percent on time

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Carrier accounts for 53% of the 19,000 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
    53%
  • Late-arriving aircraft
    31%
  • National Airspace System
    14%
  • Extreme weather
    2%

The largest share of delay minutes, 53%, 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 9,975 of the 19,000 delay minutes reported here. The split is drawn from 18,673 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 90.0% on time here.

Cancellations sit at 0.93% against a national 1.81%, which is ordinary. Diversions add another 0.21%.

Connections and stage length

What a delay here costs

7.3% 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 last an hour and a half, which a normal layover absorbs.

The 1,145 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 runs 78.4% on time across 965 flights, within half 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. 966 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 Delta on MIA to DTW

Put together: treat all of this as provisional. 966 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 77.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 955 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.