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DelayAtlas

Carrier route record

F9DTWATL

Frontier Airlines · Detroit to Atlanta

Flights
501
Period
July 2025 to June 2026
Share of route
10%
Carriers
3
CGRADE

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

Frontier on DTW to ATL draws a C. About one flight in three arrives at least 15 minutes late, and the typical late arrival is close to two hours behind schedule. Build slack into anything you connect to. That rests on 501 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 3,703 at 81.6% on time.

The national on-time rate over the same period is 77.6%, so Frontier on DTW to ATL runs 12 points behind the country as a whole. Across a thousand flights that is about 123 extra late arrivals.

Key figures

On time

65.3%

Arrivals under 15 minutes late, of 493 completed flights

Avg delay

107 min

Across delayed arrivals only, not all flights

Cancelled

1.60%

National rate is 1.81%

Whole route

79.0%

Every carrier on DTW to ATL, 4,881 flights

These figures cover 501 flights between July 2025 and June 2026. Beyond the headline rate, 15.0% 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 ATL

Frontier flew 501 of the 4,881 flights on DTW to ATL, about 10% of it. Its 65.3% on time is 14 points worse than the route as a whole, which runs 79.0%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Delta at 81.6% to Frontier at 65.3%.

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 81.6% of the time; Spirit Airlines manages 75.0%. Sample sizes sit next to every figure, because a two-point gap across 677 flights means less than a ten-point one.

On-time performance by carrier on DTW to ATL
AirlineFlightsOn timeAvg delayCancelledGrade
Delta Air Lines3,70381.6%68 min0.49%B+
Spirit Airlines67775.0%74 min1.92%B
Frontier Airlines (this page)50165.3%107 min1.60%C

Delta leads Spirit by 7 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Flight by flight

Frontier flight numbers on DTW to ATL

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 27 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am57 flights84.2%
  • 8am–11am71 flights71.4%
  • 11am–2pm99 flights60.6%
  • 2pm–5pm85 flights72.6%
  • 5pm–8pm168 flights56.8%
  • 8pm–5am21 flights

Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 56.8% on time, against 84.2% 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 5pm–8pm window is the busiest, with 168 flights scheduled in it.

Across the year

Frontier on DTW to ATL through the year

On-time rate by calendar monthJF56M69A69M67J53J61A85S70ON71D
Darker means more delays. Figures are on-time percentages.September best, July worst

July is the worst month at 52.5% on time, 32 points below September, the best at 84.6%. 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, Wednesday is the strongest day at 78.0% on time and Monday the weakest at 52.7%. 25 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week52.7Mon58.2Tue78.0Wed66.7Thu74.1Fri73.8Sat55.6Sun
Monday: 52.7 percent on time. Tuesday: 58.2 percent on time. Wednesday: 78.0 percent on time. Thursday: 66.7 percent on time. Friday: 74.1 percent on time. Saturday: 73.8 percent on time. Sunday: 55.6 percent on time

Delay causes

Why Frontier runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 69% of the 18,000 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.

  • Late-arriving aircraft
    69%
  • Carrier
    17%
  • National Airspace System
    13%
  • Extreme weather
    0%

69% 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 18,000 reported delay minutes here, that single category outweighs weather by 69 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 18,261 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 84.2% on time here.

Cancellations sit at 1.60% 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. 15.0% 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 69.2% on time across 501 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.

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 DTW to ATL

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 65.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 493 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.