Carrier route record

DLLAX→ORD

Delta Air Lines · Los Angeles to Chicago

Flights: 238
Period: September 2025 to August 2026
Share of route: 3%
Carriers: 5

Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.

Delta on LAX to ORD sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 238 flights. The strongest carrier on the route with a full sample, United Airlines, flew 3,414 at 79.9% on time.

The national on-time rate over the same period is 77.3%, so Delta on LAX to ORD runs 7 points behind the country as a whole. Across a thousand flights that is about 73 extra late arrivals.

On time

70.0%

Arrivals under 15 minutes late, of 230 completed flights

Avg delay

66 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.89%

Whole route

76.4%

Every carrier on LAX to ORD, 7,119 flights

These figures cover 238 flights between September 2025 and August 2026. Beyond the headline rate, 11.7% of arrivals land a full hour or more behind schedule, against 8.3% nationally.

Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.

Carrier by carrier

Delta against every carrier on LAX to ORD

Delta flew 238 of the 7,119 flights on LAX to ORD, about 3% of it. Its 70.0% on time is 6 points worse than the route as a whole, which runs 76.4%. Ranked by on-time rate it is number four of five carriers on the route, where the range runs from United at 79.9% to Frontier at 62.3%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. United Airlines arrives on time 79.9% of the time; American Airlines manages 73.9%. Sample sizes sit next to every figure, because a two-point gap across 3,091 flights means less than a ten-point one.

On-time performance by carrier on LAX to ORD
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	3,414	79.9%	69 min	0.70%	B+
Spirit Airlinesthin sample	132	78.9%	107 min	6.06%	B−
American Airlines	3,091	73.9%	92 min	1.78%	C
Delta Air Lines (this page)thin sample	238	70.0%	66 min	0.00%	C+
Frontier Airlinesthin sample	244	62.3%	135 min	4.92%	D−

United leads American by 6 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.

Departure window

When Delta runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 17 points, against 6 points between the best and worst carrier.

5am–8am81 flights77.9%
8am–11am5 flights—
11am–2pm66 flights72.3%
2pm–5pm—
5pm–8pm86 flights61.4%
8pm–5am—

Scale runs 55% to 85%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 61.4% on time, against 77.9% 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 86 flights scheduled in it.

Across the year

Delta on LAX to ORD through the year

Apr–Jun 202666 flights68.3%
Jul–Sep 2026172 flights70.7%

Scale runs 60% to 75%.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 70.0% on time across 238 flights.

Split by quarter, Delta on LAX to ORD logged 66 flights in Apr–Jun 2026 and 172 flights in Jul–Sep 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 70.0% annual figure is the one to use.

Across the week, Tuesday is the strongest day at 82.9% on time and Sunday the weakest at 60.0%, a spread of 23 points.

Arrival by arrival

How late Delta on LAX to ORD runs when it is late

The 69 late arrivals split 17 under half an hour, 25 between 30 and 60 minutes, and 27 an hour or more.

15+ min early55 flights23.9%
Within 15 min106 flights46.1%
15–29 min late17 flights7.4%
30–59 min late25 flights10.9%
1–2 hours late17 flights7.4%
2+ hours late10 flights4.3%

Scale runs 0% to 100%.

Share of 230 completed flights by arrival against schedule.

13 of 57 late departures made up the time and arrived on time, 23% of them. In the other direction, 25 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at ORD.

The worst days

Worst days for Delta on LAX to ORD

The latest arrival of the period was on 8 June 2026, 4 hours 41 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. Three of the five worst days fell in June 2026.

The latest arrivals of Delta on LAX to ORD in the period
Date	Arrived late by	Largest filed cause
8 June 2026	4 hours 41 minutes	National Airspace System
10 June 2026	3 hours 31 minutes	National Airspace System
11 August 2026	3 hours 17 minutes	National Airspace System
14 July 2026	3 hours 8 minutes	Carrier
14 June 2026	2 hours 53 minutes	Late-arriving aircraft

Delay causes

Why Delta runs late on this route

National Airspace System accounts for 59% of the 4,556 delay minutes carriers reported here, and the remaining four split what is left.

National Airspace System
59%
Carrier
29%
Late-arriving aircraft
12%

59% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 2,709 minutes out of 4,556, against a national NAS share of 21%. The split is drawn from 4,556 reported delay minutes.

Cancellations are rare at 0.00%, below the national 1.89% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.

Connections and stage length

What a delay here costs

11.7% 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.

At 1,744 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The return leg runs 70.6% on time across 238 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 238 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 Delta on LAX to ORD

Put together: treat all of this as provisional. 238 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 70.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 230 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures