Route reliability record
ATL→DTW
Atlanta to Detroit
- Flights
- 4,921
- Period
- June 2025 to May 2026
- Distance
- 594 mi
- Carriers
- 3
This route lands a B+, level with the national rate of 77.4%. About one flight in four arrive 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 4,921 flights, of which Delta Air Lines flew 3,693 at 77.9% on time.
Delta Air Lines is the most reliable of the three carriers covered here at 77.9% on time across 3,693 flights.
Key figures
On time
76.7%
Arrivals under 15 minutes late, of 4,872 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
0.87%
National rate is 1.80%
Best carrier
Delta
77.9% on time across 3,693 flights
These figures cover 4,921 flights between June 2025 and May 2026. The median arrival is 4 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
Which airline is most reliable on ATL to DTW
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 77.9% of the time; Frontier Airlines manages 70.6%. Sample sizes sit next to every figure, because a two-point gap across 477 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 3,693 | 77.9% | 59 min | 0.57% | B+ |
| Spirit Airlines | 751 | 74.7% | 80 min | 1.86% | C |
| Frontier Airlines | 477 | 70.6% | 68 min | 1.68% | C |
Delta leads Frontier by 7 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 26 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am813 flights90.2%
- 8am–11am617 flights79.4%
- 11am–2pm910 flights80.0%
- 2pm–5pm863 flights74.7%
- 5pm–8pm736 flights74.5%
- 8pm–5am982 flights64.3%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 64.3% on time, against 90.2% 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.
Across the year
When delays peak on this route
This route's year swings by 24 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.
June is the worst month at 64.4% on time, 24 points below September, the best at 87.9%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck.
Across the week, Wednesday is the strongest day at 83.8% on time and Sunday the weakest at 71.0%. 13 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 47% of the 72,000 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.
- 47%Carrier
- 32%Late-arriving aircraft
- 15%National Airspace System
- 6%Extreme weather
- 0%Security
The largest share of delay minutes, 47%, 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 34,000 of the 72,000 delay minutes reported here.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 90.2% on time here.
Cancellations are rare at 0.87%, below the national 1.80% 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
7.8% of arrivals land an hour or more late, close to the national 8.2%. 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 about an hour kind, which a normal layover absorbs.
The 594 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 77.8% on time across 4,934 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.
The sample behind these figures is 4,921 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. September runs 87.9% on time and June 64.4%, a swing of 24 points. If the dates move at all, move them out of June before you think about anything else.
Common questions
ATL to DTW questions
How often is ATL to DTW 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 23.3% of the 4,921 flights in this analysis, against 22.6% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on ATL to DTW?
Delta Air Lines leads at 77.9% on time across 3,693 flights. Frontier Airlines is at the other end on 70.6%, a gap of 7 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 ATL to DTW?
The 5am–8am departure window is the strongest at 90.2% on time. The 8pm–5am window is the weakest at 64.3%, 26 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 June delays on ATL to DTW?
June is the weakest month at 64.4% on time, compared with 87.9% in September. Across the year that is 24 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- DTW to ATL — the return legseparate record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Detroit Metropolitan Wayne County (DTW) delay statistics
- Delta Air Lines on-time record77.9%
- Spirit Airlines on-time record74.7%
- Frontier Airlines on-time record70.6%
- The best time of day to fly, according to 7.05 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. ATL to DTW and DTW to ATL 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, June 2025 to May 2026. Updated monthly. How this data is collected.