Flight number record
DL 2631
Delta Air Lines · Fort Lauderdale to Detroit
- Route
- FLL → DTW
- Departs
- 06:00
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 2631, check with Delta Air Lines.
DL 2631 earns an A. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 14 points better than the national rate of 77.3%. When something does go wrong the average delay runs a little over an hour. That rests on 365 flights, with a median arrival 10 minutes early.
Set against the rest of the country, DL 2631's record is 14 points better than the US average of 77.3%. That gap is worth roughly 140 fewer late arrivals for every thousand flights.
Key figures
On time
91.3%
Arrivals under 15 minutes late, of 358 completed flights
Avg delay
79 min
Across delayed arrivals only, not all flights
Cancelled
1.92%
National rate is 1.89%
1 hour+ late
2.8%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 10 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.
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Schedule
When DL 2631 flies
DL 2631 flies FLL to DTW without a single fixed slot. Its most common scheduled departure was 06:00, used on 265 of 365 flights, with 06:30 (53 flights) next.
- Departs 06:00265 flights72.6%
- Departs 06:3053 flights14.5%
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 06:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 2631 runs 2 points better at 91.3%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
DL 2631 next to FLL to DTW
Every carrier on FLL to DTW combined arrived on time 72.3% of the time across 2,705 flights, so DL 2631 is 19 points ahead of it. Delta flew 1,810 flights on the same city pair under all its flight numbers, including this one, and those ran 78.6% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 10 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 2631 | 365 | 91.3% | 79 min | 1.92% | A |
| All Delta Air Lines on FLL–DTW | 1,810 | 78.6% | 70 min | 1.55% | B |
| All carriers on FLL–DTW | 2,705 | 72.3% | 73 min | 2.14% | C |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 2631 quarter by quarter
DL 2631 did not run the same all year. Its best quarter was Jul–Sep 2025 at 100.0% on time and its weakest Oct–Dec 2025 at 85.6%, a swing of 14 points on roughly 73 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 flights100.0%
- Oct–Dec 202592 flights85.6%
- Jan–Mar 202690 flights88.6%
- Apr–Jun 202691 flights97.8%
- Jul–Sep 202662 flights90.0%
Scale runs 75% to 100%.
By weekday, DL 2631 ranged from 85.7% on Tuesday to 94.1% on Sunday. With about 52 flights behind each day, a spread of 8 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late DL 2631 runs when it is late
DL 2631 often beats the schedule: 114 of 358 completed flights, 32%, arrived 15 minutes or more early. The 31 late arrivals split 14 under half an hour, 7 between 30 and 60 minutes, and 10 an hour or more.
- 15+ min early114 flights31.8%
- Within 15 min213 flights59.5%
- 15–29 min late14 flights3.9%
- 30–59 min late7 flights2.0%
- 1–2 hours late5 flights1.4%
- 2+ hours late5 flights1.4%
Scale runs 0% to 100%.
Share of 358 completed flights by arrival against schedule.
5 of 28 late departures made up the time and arrived on time, 18% of them. 8 flights left on time and still arrived late.
The worst days
Worst days for DL 2631
The latest arrival of the period was on 24 December 2025, 7 hours 51 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On three of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 24 December 2025 | 7 hours 51 minutes | Late-arriving aircraft |
| 19 March 2026 | 6 hours 4 minutes | Carrier |
| 10 March 2026 | 5 hours 12 minutes | Carrier |
| 16 April 2026 | 2 hours 27 minutes | Carrier |
| 5 December 2025 | 2 hours 2 minutes | Late-arriving aircraft |
Delay causes
Why DL 2631 runs late
Carrier accounts for 58% of the 2,432 delay minutes carriers reported here, and the remaining four split what is left.
- 58%Carrier
- 31%Late-arriving aircraft
- 10%National Airspace System
The largest share of delay minutes, 58%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,414 of the 2,432 delay minutes reported here. The split is drawn from 2,432 delay minutes reported on DL 2631.
Cancellations sit at 1.92% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 2.8% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 1,127 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
Every one of the 365 flights under DL 2631 in the data flew FLL to DTW. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 365 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 2631
For a booking, read DL 2631 as 91.3% on time with 1.92% cancelled over 365 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- FLL to DTW, every carrier and departure
- DTW to FLL, the return direction
- Delta Air Lines 655 on the same route81.1%
- Fort Lauderdale-Hollywood International (FLL) delay statistics
- Detroit Metropolitan Wayne County (DTW) 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
- Worst months to fly in the US, ranked by the data
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.