Flight number record

DL 1665

Delta Air Lines · Detroit to Chicago

Route: DTW → ORD
Departs: 20:00
Flights: 306
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1665, check with Delta Air Lines.

DL 1665 draws a C−. About one flight in three arrives at least 15 minutes late, and the typical late arrival is an hour and a half behind schedule. Build slack into anything you connect to. That rests on 306 flights, with a median arrival 2 minutes late.

The national on-time rate over the same period is 77.6%, so DL 1665 runs 12 points behind the country as a whole. Across a thousand flights that is about 121 extra late arrivals.

On time

65.5%

Arrivals under 15 minutes late, of 296 completed flights

Avg delay

94 min

Across delayed arrivals only, not all flights

Cancelled

3.27%

National rate is 1.81%

1 hour+ late

15.9%

National rate is 8.1%

These figures cover 306 flights between July 2025 and June 2026. Beyond the headline rate, 15.9% 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.

Schedule

When DL 1665 flies

DL 1665 flies DTW to ORD without a single fixed slot. Its most common scheduled departure was 20:00, used on 101 of 306 flights, with 20:38 (38 flights) and 19:45 (32 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 20:00101 flights33.0%
Departs 20:3838 flights12.4%
Departs 19:4532 flights10.5%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.

A 20:00 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.5%, and DL 1665 runs 5 points worse at 65.5%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

DL 1665 next to DTW to ORD

Every carrier on DTW to ORD combined arrived on time 72.0% of the time across 5,959 flights, so DL 1665 is 7 points behind it. Delta flew 1,258 flights on the same city pair under all its flight numbers, including this one, and those ran 70.9% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 16 points.

DL 1665 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 1665thin sample	306	65.5%	94 min	3.27%	C−
All Delta Air Lines on DTW–ORD	1,258	70.9%	82 min	2.54%	C
All carriers on DTW–ORD	5,959	72.0%	90 min	3.02%	C−
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 1665 quarter by quarter

DL 1665 did not run the same all year. Its best quarter was Oct–Dec 2025 at 78.4% on time and its weakest Jul–Sep 2025 at 59.3%, a swing of 19 points on roughly 77 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Jul–Sep 202592 flights59.3%
Oct–Dec 202537 flights78.4%
Jan–Mar 202686 flights69.5%
Apr–Jun 202691 flights62.8%

Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, DL 1665 did best on Sunday at 71.4% on time and worst on Saturday at 58.5%. Each day rests on about 44 flights, so a gap of 13 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 1665 runs late

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 9,621 reported delay minutes.

Carrier
32%
National Airspace System
31%
Late-arriving aircraft
28%
Extreme weather
8%

No single cause dominates. carrier at 32%, national airspace system at 31% and late-arriving aircraft at 28% split the 9,621 reported delay minutes between them. An even spread like this usually means the operation is running close to its designed capacity with no one obvious weak point, and it is the hardest pattern for a traveller to route around. The split is drawn from 9,621 delay minutes reported on DL 1665.

Cancellations run at 3.27%, against 1.81% 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.

Connections and routes

What a delay on this flight costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 15.9% 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 same number turns up on three other city pairs in the data, including ATL to TPA (40), TPA to ATL (40) and ORD to DTW (32), but none flew often enough under DL 1665 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DTW to ORD only.

One caution: this is a thin sample. 306 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 DL 1665

For a booking, the cancellation rate is the figure to plan around on DL 1665: 3.27% of its 306 scheduled flights did not operate. A late arrival costs an hour and a half, but a cancellation costs the day, so leave a later option open.

Where to go next

A flight number here means Delta Air Lines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.

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.

Key figures