Carrier route record
F9ATL→DTW
Frontier Airlines · Atlanta to Detroit
- Flights
- 501
- Period
- July 2025 to June 2026
- Share of route
- 10%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on ATL to DTW sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 8 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 501 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 3,698 at 79.5% on time.
The national on-time rate over the same period is 77.6%, so Frontier on ATL to DTW runs 8 points behind the country as a whole. Across a thousand flights that is about 84 extra late arrivals.
Key figures
On time
69.2%
Arrivals under 15 minutes late, of 494 completed flights
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
1.40%
National rate is 1.81%
Whole route
78.0%
Every carrier on ATL to DTW, 4,871 flights
These figures cover 501 flights between July 2025 and June 2026. Beyond the headline rate, 11.1% 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 ATL to DTW
Frontier flew 501 of the 4,871 flights on ATL to DTW, about 10% of it. Its 69.2% on time is 9 points worse than the route as a whole, which runs 78.0%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Delta at 79.5% to Frontier at 69.2%.
The two carriers here are closely matched: 3 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 3,698 | 79.5% | 57 min | 0.51% | B+ |
| Spirit Airlines | 672 | 76.4% | 81 min | 2.08% | B |
| Frontier Airlines (this page) | 501 | 69.2% | 71 min | 1.40% | C |
No carrier stands out. Delta tops the table at 79.5%, 3 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 39 points, against 3 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am96 flights83.2%
- 8am–11am95 flights64.9%
- 11am–2pm99 flights75.5%
- 2pm–5pm146 flights67.6%
- 5pm–8pm8 flights—
- 8pm–5am57 flights43.9%
Scale runs 35% to 90%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 43.9% on time, against 83.2% 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. The 2pm–5pm window is the busiest, with 146 flights scheduled in it.
Across the year
Frontier on ATL to DTW through the year
July is the worst month at 50.0% on time, 42 points below September, the best at 92.3%. 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. May was the busiest month here, with 62 flights.
Across the week, Friday is the strongest day at 80.5% on time and Monday the weakest at 55.4%. 25 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. Late-arriving aircraft accounts for 66% of the 11,000 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.
- 66%Late-arriving aircraft
- 28%Carrier
- 6%National Airspace System
- 0%Extreme weather
66% 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 11,000 reported delay minutes here, that single category outweighs weather by 66 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 10,720 reported delay minutes.
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 83.2% on time here.
Cancellations sit at 1.40% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
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. 11.1% 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.
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 is a different operation and performs like one: it runs 65.3% on time across 501 flights, 4 points below 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.
One caution: this is a thin sample. 501 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 ATL to DTW
Put together: treat all of this as provisional. 501 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 69.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 494 completed flights over 12 months sit behind that.
Related
Where to go next
- ATL to DTW, every carrier
- Frontier on DTW to ATL, the return leg
- Delta Air Lines on ATL to DTW79.5%
- Spirit Airlines on ATL to DTW76.4%
- Frontier Airlines network-wide record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Detroit Metropolitan Wayne County (DTW) delay statistics
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
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.