Route reliability record
DAL→ATL
Dallas to Atlanta
- Flights
- 3,398
- Period
- July 2025 to June 2026
- Distance
- 721 mi
- Carriers
- 2
This route lands a B, 2 points better than the national rate of 77.6%. About one flight in five 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 3,398 flights, of which Delta Air Lines flew 1,851 at 82.1% 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.
Key figures
On time
79.2%
Arrivals under 15 minutes late, of 3,325 completed flights
Avg delay
74 min
Across delayed arrivals only, not all flights
Cancelled
1.94%
National rate is 1.81%
Best carrier
Delta
82.1% on time across 1,851 flights
These figures cover 3,398 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
Which airline is most reliable on DAL to ATL
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 82.1% of the time; Southwest Airlines manages 75.6%. Sample sizes sit next to every figure, because a two-point gap across 1,547 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 1,851 | 82.1% | 90 min | 2.11% | B |
| Southwest Airlines | 1,547 | 75.6% | 60 min | 1.75% | B |
Delta leads Southwest 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 30 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am643 flights89.2%
- 8am–11am742 flights88.4%
- 11am–2pm567 flights82.0%
- 2pm–5pm710 flights71.3%
- 5pm–8pm645 flights67.5%
- 8pm–5am91 flights59.6%
Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 59.6% on time, against 89.2% 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 8am–11am window is the busiest, with 742 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 18 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.
September is the best month on the calendar at 87.5% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. October was the busiest month here, with 316 flights.
Across the week, Tuesday is the strongest day at 82.7% on time and Sunday the weakest at 76.1%. 7 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. Late-arriving aircraft accounts for 43% of the 51,000 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.
- 43%Late-arriving aircraft
- 33%Carrier
- 14%National Airspace System
- 9%Extreme weather
- 0%Security
43% 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 51,000 reported delay minutes here, that single category outweighs weather by 5 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 51,002 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 89.2% on time here.
Cancellations sit at 1.94% against a national 1.81%, which is ordinary. Diversions add another 0.21%.
Connections and stage length
What a delay here actually costs
7.6% 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.
The 721 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 81.3% on time across 3,398 flights, within 2 points 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 3,398 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 87.5% on time and May 69.4%, a swing of 18 points. If the dates move at all, move them out of May before you think about anything else. 3,325 completed flights over 12 months sit behind that.
Common questions
DAL to ATL questions
How often is DAL to ATL delayed?
About one flight in five arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 20.8% of the 3,398 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 DAL to ATL?
Delta Air Lines leads at 82.1% on time across 1,851 flights. Southwest Airlines is at the other end on 75.6%, 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 DAL to ATL?
The 5am–8am departure window is the strongest at 89.2% on time. The 8pm–5am window is the weakest at 59.6%, 30 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 May delays on DAL to ATL?
May is the weakest month at 69.4% on time, compared with 87.5% in September. Across the year that is 18 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
- ATL to DAL — the return legseparate record
- Dallas Love Field (DAL) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Delta Air Lines on-time record82.1%
- Southwest Airlines on-time record75.6%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. DAL to ATL and ATL to DAL 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.