Airline on-time record
DL
Delta Air Lines
- Flights
- 1,039,445
- Period
- June 2025 to May 2026
- Airports
- 25
- US rank
- #2 by volume
Delta Air Lines lands a B, 4 points better than the national rate of 77.4%. 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 1,039,445 flights, of which Phoenix (PHX) flew 10,708 at 86.6% on time.
Phoenix (PHX) is the most reliable of the 25 airports covered here at 86.6% on time across 10,708 flights.
Key figures
On time
80.9%
National average is 77.4%
Avg delay
72 min
Across delayed flights only
Cancelled
1.67%
National rate is 1.80%
Largest base
ATL
241,168 departures, 78.4% on time
These figures cover 1.04 million flights between June 2025 and May 2026. The median arrival is 8 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.
Airport by airport
Where Delta Air Lines runs well, and where it does not
The choice of airport is not cosmetic here. Phoenix (PHX) arrives on time 86.6% of the time; Chicago (ORD) manages 72.6%. Sample sizes sit next to every figure, because a two-point gap across 10,533 flights means less than a ten-point one.
| Airport | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| ATL · Atlanta | 241,168 | 78.4% | 60 min | 1.72% | B |
| MSP · Minneapolis | 65,165 | 79.0% | 63 min | 1.09% | B |
| DTW · Detroit | 60,438 | 77.5% | 66 min | 1.31% | B |
| SLC · Salt Lake City | 54,627 | 83.5% | 62 min | 0.75% | B+ |
| LAX · Los Angeles | 37,232 | 81.3% | 68 min | 1.08% | B |
| SEA · Seattle | 32,222 | 81.5% | 65 min | 1.07% | B |
| JFK · New York | 30,747 | 77.6% | 73 min | 2.55% | B |
| LGA · New York | 29,677 | 73.9% | 79 min | 3.80% | C− |
| BOS · Boston | 26,395 | 76.5% | 73 min | 1.97% | B |
| MCO · Orlando | 21,391 | 77.0% | 84 min | 1.87% | B |
| LAS · Las Vegas | 15,922 | 85.0% | 77 min | 1.06% | A |
| TPA · Tampa | 13,976 | 79.7% | 78 min | 1.65% | B |
| SFO · San Francisco | 13,738 | 80.0% | 70 min | 1.21% | B |
| AUS · Austin | 12,986 | 81.9% | 81 min | 1.44% | B |
| FLL · Fort Lauderdale | 12,883 | 76.2% | 79 min | 2.17% | B |
| RDU · Raleigh | 12,085 | 84.4% | 79 min | 1.59% | B |
| DFW · Dallas-Fort Worth | 11,826 | 80.7% | 88 min | 2.47% | B |
| MIA · Miami | 11,630 | 72.8% | 82 min | 2.10% | C |
| DEN · Denver | 11,605 | 82.4% | 79 min | 1.36% | B |
| PHX · Phoenix | 10,708 | 86.6% | 84 min | 1.06% | A |
| ORD · Chicago | 10,533 | 72.6% | 91 min | 2.39% | C |
| SAN · San Diego | 9,609 | 86.3% | 74 min | 1.09% | A |
| DCA · Washington | 9,457 | 78.0% | 93 min | 2.51% | B |
| BNA · Nashville | 9,282 | 84.6% | 84 min | 1.83% | B |
| IAH · Houston | 8,344 | 80.3% | 86 min | 1.89% | B |
New York (LGA) cancels 3.8% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Route by route
Busiest Delta Air Lines routes
These are the 25 routes Delta Air Lines flies most often, each against its network-wide 80.9%. Route-level variation inside a single airline is routinely wider than the gap between two airlines nationally.
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| ATL to MCO | 5,462 | 68.4% | 64 min | 1.17% | C |
| MCO to ATL | 5,460 | 77.4% | 89 min | 1.25% | B |
| ATL to LGA | 4,937 | 75.4% | 67 min | 2.96% | B |
| LGA to ATL | 4,934 | 78.7% | 74 min | 3.02% | B− |
| TPA to ATL | 4,426 | 80.3% | 77 min | 1.22% | B |
| ATL to TPA | 4,426 | 72.7% | 58 min | 1.22% | C |
| ATL to FLL | 4,256 | 71.3% | 57 min | 1.55% | C |
| FLL to ATL | 4,252 | 77.6% | 75 min | 1.65% | B |
| ATL to LAX | 3,875 | 78.8% | 57 min | 0.85% | B+ |
| LAX to ATL | 3,871 | 79.7% | 64 min | 0.96% | B+ |
| DCA to ATL | 3,830 | 80.1% | 88 min | 2.87% | B |
| ATL to DCA | 3,830 | 65.9% | 60 min | 2.64% | C |
| ATL to JAX | 3,828 | 74.2% | 59 min | 1.52% | C |
| JAX to ATL | 3,828 | 85.3% | 82 min | 1.59% | A |
| ATL to RDU | 3,801 | 81.6% | 56 min | 1.29% | B |
| RDU to ATL | 3,801 | 88.4% | 81 min | 1.42% | A |
| ATL to PBI | 3,760 | 74.1% | 54 min | 1.54% | C |
| PBI to ATL | 3,760 | 82.8% | 64 min | 1.54% | B |
| DTW to ATL | 3,701 | 80.2% | 68 min | 0.57% | B+ |
| ATL to DTW | 3,693 | 77.9% | 59 min | 0.57% | B+ |
| ATL to BOS | 3,658 | 75.2% | 60 min | 1.80% | B |
| BOS to ATL | 3,656 | 81.3% | 73 min | 1.86% | B |
| ATL to BNA | 3,360 | 79.9% | 54 min | 2.11% | B |
| BNA to ATL | 3,359 | 86.5% | 72 min | 2.20% | A |
| JFK to LAX | 3,357 | 78.2% | 74 min | 1.76% | B |
Departure window
The best time of day to fly Delta Air Lines
Departure time matters more here than the choice of airport. The gap between the best and worst window is 17 points, against 14 points between the best and worst airport. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am182,868 flights90.1%
- 8am–11am179,095 flights86.2%
- 11am–2pm189,400 flights82.2%
- 2pm–5pm176,608 flights76.5%
- 5pm–8pm168,203 flights73.4%
- 8pm–5am143,271 flights74.8%
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 90.1% of the time, against 73.4% for the evening window. That is 17 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on.
Across the year
Delta Air Lines through the calendar
Delta's year swings by 14 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 73.8% on time, 14 points below September, the best at 87.6%. 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.
Across the week, Wednesday is the strongest day at 84.1% on time and Sunday the weakest at 76.8%. 7 points is a smaller lever than departure hour, but it is free.
Delay causes
What holds Delta Air Lines up
One category carries most of the weight here. Carrier accounts for 44% of the 14.0 million 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.
- 44%Carrier
- 30%Late-arriving aircraft
- 21%National Airspace System
- 4%Extreme weather
- 0%Security
The largest share of delay minutes, 44%, 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 airports on the same schedule is genuinely earned. It accounts for 6.22 million of the 14.0 million 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 90.1% on time here.
Cancellations sit at 1.67% against a national 1.80%, which is ordinary. Diversions add another 0.27%.
6.8% 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 a little over an hour kind, which a normal layover absorbs.
1,039,445 flights sit behind these numbers, which is a large enough sample that the headline rate is not moving on noise. Where a sub-group falls below 30 flights the site shows a dash instead of a percentage.
What to do with this
Booking Delta Air Lines
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 87.6% on time and June 73.8%, a swing of 14 points. If the dates move at all, move them out of June before you think about anything else.
Common questions
Delta Air Lines reliability questions
How often is Delta Air Lines 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 19.1% of the 1,039,445 flights in this analysis, against 22.6% nationally. Delayed flights are late by a little over an hour on average.
Which airport does Delta Air Lines run best from?
Phoenix (PHX) leads at 86.6% on time across 10,708 flights. Chicago (ORD) is at the other end on 72.6%, a gap of 14 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 Delta Air Lines?
The 5am–8am departure window is the strongest at 90.1% on time. The 5pm–8pm window is the weakest at 73.4%, 17 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 Delta Air Lines?
June is the weakest month at 73.8% on time, compared with 87.6% in September. Across the year that is 14 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
- Delta Air Lines at ATL — Atlanta78.4%
- Delta Air Lines at MSP — Minneapolis79.0%
- Delta Air Lines at DTW — Detroit77.5%
- Delta Air Lines at SLC — Salt Lake City83.5%
- Delta Air Lines at LAX — Los Angeles81.3%
- ATL to MCO route record68.4%
- MCO to ATL route record77.4%
- ATL to LGA route record75.4%
- LGA to ATL route record78.7%
- The best time of day to fly, according to 7.05 million flight records
- Do budget airlines really get delayed more? The numbers
Source: US DOT Bureau of Transportation Statistics, on-time performance data, June 2025 to May 2026. Updated monthly. How this data is collected.