Carrier performance at one airport
DL→ORD
Delta Air Lines at Chicago O'Hare International
- Departures
- 10,687
- Period
- September 2025 to August 2026
- Routes
- 8
- Rank here
- #5 of 12
Delta Air Lines at Chicago sits in the middle of the pack with a C−. About seven flights in ten arrive on time by the DOT's definition, 5 points worse than the national rate of 77.3%. The late ones land an hour and a half behind schedule. That rests on 10,687 flights, of which Envoy Air flew 57,966 at 76.1% on time.
Measured against the airport rather than the country, Delta Air Lines runs about a point ahead of the 70.7% weighted average across all carriers at ORD. That is the comparison worth making: every operator here works the same runways, the same airspace and the same weather.
Key figures
On time
72.0%
10,306 completed departures
Avg delay
91 min
Across delayed flights only
Cancelled
3.13%
At ORD, this carrier only
Rank here
#5
Of 12 carriers clearing the floor at ORD
These figures cover 11,000 flights between September 2025 and August 2026. Beyond the headline rate, 12.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
Against the competition
Every carrier at ORD, ranked
The choice of carrier is not cosmetic here. Envoy Air arrives on time 76.1% of the time; PSA Airlines manages 60.2%. Sample sizes sit next to every figure, because a two-point gap across 2,832 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Envoy Air | 57,966 | 76.1% | 65 min | 2.93% | B |
| Republic Airways | 33,415 | 76.1% | 74 min | 3.81% | B− |
| JetBlue Airways | 1,293 | 73.1% | 99 min | 6.34% | C− |
| United Airlines | 102,132 | 73.0% | 73 min | 1.30% | C |
| Delta Air Lines (this page) | 10,687 | 72.0% | 91 min | 3.13% | C− |
| Southwest Airlines | 3,139 | 71.3% | 70 min | 1.40% | C |
| Frontier Airlines | 4,179 | 67.7% | 109 min | 3.76% | C− |
| Alaska Airlines | 3,346 | 67.4% | 70 min | 1.82% | C |
| American Airlines | 61,506 | 66.4% | 82 min | 2.56% | C |
| SkyWest Airlines | 78,955 | 65.8% | 88 min | 4.06% | C− |
| Spirit Airlines | 3,558 | 63.4% | 83 min | 5.99% | D− |
| PSA Airlines | 2,832 | 60.2% | 127 min | 7.06% | D− |
PSA Airlines cancels 7.1% 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
Where Delta Air Lines flies from ORD
Delta Air Lines operates 8 routes out of ORD with enough volume to report. Route records inside one carrier at one airport still spread widely, because a short shuttle and a transcontinental have very different exposure to a late inbound.
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| ORD to ATL · Atlanta | 2,629 | 79.8% | 84 min | 2.40% | B |
| ORD to LGA · New York | 2,309 | 68.7% | 96 min | 5.89% | C− |
| ORD to MSP · Minneapolis | 1,424 | 66.5% | 94 min | 2.74% | C |
| ORD to DTW · Detroit | 1,156 | 77.3% | 96 min | 3.20% | B− |
| ORD to SLC · Salt Lake City | 1,014 | 70.4% | 109 min | 1.18% | C |
| ORD to BOS · Boston | 981 | 67.4% | 90 min | 3.47% | C− |
| ORD to SEA · Seattle | 922 | 66.0% | 67 min | 1.41% | C |
| ORD to LAX · Los Angelesthin sample | 238 | 70.6% | 83 min | 0.00% | C+ |
Flight by flight
Delta Air Lines flight numbers from ORD
6 Delta Air Lines flight numbers leaving ORD flew their main route often enough to have a record of their own. Grouped by destination.
Departure window
Best time of day for this operation
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 23 points, against 16 points between the best and worst carrier.
- 5am–8am2,729 flights83.7%
- 8am–11am1,995 flights78.2%
- 11am–2pm1,292 flights74.3%
- 2pm–5pm1,646 flights62.9%
- 5pm–8pm2,556 flights60.8%
- 8pm–5am469 flights60.9%
Scale runs 50% to 90%.
The 5pm–8pm window is where this operation falls apart: 60.8% on time, against 83.7% 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 5am–8am window is the busiest, with 2,729 flights scheduled in it.
Across the year
Seasonal pattern
December is the weak month at 54.5% on time, against 81.6% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 1,155 flights.
Delay causes
What holds this operation up
- 41%Late-arriving aircraft
- 33%Carrier
- 20%National Airspace System
- 5%Extreme weather
41% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 263,000 reported delay minutes here, that single category outweighs weather by 8 to one. The split is drawn from 262,644 reported delay minutes.
Cancellations run at 3.13%, against 1.89% nationally. That is about one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
12.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The sample behind these figures is 10,687 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.
Put together: the delay figures matter less here than the 3.13% cancellation rate. A late arrival costs you an hour and a half; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 10,306 completed flights over 12 months sit behind that.
Common questions
Delta Air Lines at ORD
How often is Delta Air Lines at ORD delayed?
Roughly one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 28.0% of the 10,687 flights in this analysis, against 22.7% nationally. Delayed flights are late by an hour and a half on average.
Which airline is most reliable on Delta Air Lines at ORD?
Envoy Air leads at 76.1% on time across 57,966 flights. PSA Airlines is at the other end on 60.2%, a gap of 16 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 at ORD?
The 5am–8am departure window is the strongest at 83.7% on time. The 5pm–8pm window is the weakest at 60.8%, 23 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 December delays on Delta Air Lines at ORD?
December is the weakest month at 54.5% on time, compared with 81.6% in September. Across the year that is 27 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
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.