Flight number record
DL 1665
Delta Air Lines · Detroit to Chicago
- Route
- DTW → ORD
- Departs
- 20:00
- Flights
- 306
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1665, check with Delta Air Lines.
DL 1665 draws a D−. 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 3 minutes late.
The national on-time rate over the same period is 77.3%, so DL 1665 runs 13 points behind the country as a whole. Across a thousand flights that is about 134 extra late arrivals.
Key figures
On time
63.9%
Arrivals under 15 minutes late, of 294 completed flights
Avg delay
87 min
Across delayed arrivals only, not all flights
Cancelled
3.59%
National rate is 1.89%
1 hour+ late
17.0%
National rate is 8.3%
These figures cover 306 flights between September 2025 and August 2026. Beyond the headline rate, 17.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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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 88 of 306 flights, with 20:38 (38 flights) and 19:45 (31 flights) next.
- Departs 20:0088 flights28.8%
- Departs 20:3838 flights12.4%
- Departs 19:4531 flights10.1%
Scale runs 0% to 100%.
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 70.1%, and DL 1665 runs 6 points worse at 63.9%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
DL 1665 next to DTW to ORD
Every carrier on DTW to ORD combined arrived on time 72.2% of the time across 6,014 flights, so DL 1665 is 8 points behind it. Delta flew 1,156 flights on the same city pair under all its flight numbers, including this one, and those ran 69.9% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 17 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1665thin sample | 306 | 63.9% | 87 min | 3.59% | D− |
| All Delta Air Lines on DTW–ORD | 1,156 | 69.9% | 81 min | 3.20% | C− |
| All carriers on DTW–ORD | 6,014 | 72.2% | 92 min | 3.11% | C− |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | 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 2026 at 47.5%, a swing of 31 points on roughly 61 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 202530 flights66.7%
- Oct–Dec 202537 flights78.4%
- Jan–Mar 202686 flights69.5%
- Apr–Jun 202691 flights62.8%
- Jul–Sep 202662 flights47.5%
Scale runs 40% to 85%.
By weekday, DL 1665 did best on Wednesday at 74.4% on time and worst on Saturday at 55.0%. Each day rests on about 44 flights, so a gap of 19 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 1665 runs when it is late
The 106 late arrivals split 33 under half an hour, 23 between 30 and 60 minutes, and 50 an hour or more.
- 15+ min early48 flights16.3%
- Within 15 min140 flights47.6%
- 15–29 min late33 flights11.2%
- 30–59 min late23 flights7.8%
- 1–2 hours late28 flights9.5%
- 2+ hours late22 flights7.5%
Scale runs 0% to 100%.
Share of 294 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 91 departures that left 15 minutes late or more, only 7 made it up before arrival. In the other direction, 22 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 DL 1665
The latest arrival of the period was on 9 January 2026, 11 hours 22 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On three of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 9 January 2026 | 11 hours 22 minutes | Carrier |
| 2 April 2026 | 8 hours 33 minutes | Extreme weather |
| 10 June 2026 | 5 hours 58 minutes | Late-arriving aircraft |
| 9 June 2026 | 5 hours 25 minutes | Late-arriving aircraft |
| 13 March 2026 | 4 hours 38 minutes | Late-arriving aircraft |
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 9,232 reported delay minutes.
- 42%Carrier
- 25%National Airspace System
- 24%Late-arriving aircraft
- 9%Extreme weather
The largest share of delay minutes, 42%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 3,842 of the 9,232 delay minutes reported here. The split is drawn from 9,232 delay minutes reported on DL 1665.
Cancellations run at 3.59%, 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.
Connections and routes
What a delay on this flight costs
17.0% 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 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: 3.59% 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.
Related
Where to go next
- DTW to ORD, every carrier and departure
- ORD to DTW, the return direction
- United Airlines 426 on the same route70.7%
- Detroit Metropolitan Wayne County (DTW) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- Delta Air Lines on-time record
- Every Delta Air Lines flight number with a record
- The most and least reliable flight numbers in the US
- What a cancellation rate actually tells you (and what it hides)
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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.