Carrier route record
DLDTW→BUF
Delta Air Lines · Detroit to Buffalo
- Flights
- 443
- Period
- September 2025 to August 2026
- Share of route
- 34%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on DTW to BUF lands a B, level with the national rate of 77.3%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by close to two hours on average. That rests on 443 flights, with a median arrival 7 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Delta on DTW to BUF from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.0%
Arrivals under 15 minutes late, of 432 completed flights
Avg delay
103 min
Across delayed arrivals only, not all flights
Cancelled
2.48%
National rate is 1.89%
Whole route
79.2%
Every carrier on DTW to BUF, 1,294 flights
These figures cover 443 flights between September 2025 and August 2026. Beyond the headline rate, 8.6% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Delta against every carrier on DTW to BUF
Delta flew 443 of the 1,294 flights on DTW to BUF, about 34% of it. Its 78.0% on time is about level with the route as a whole at 79.2%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Republic at 100.0% to Delta at 78.0%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Republic Airwaysthin sample | 7 | 100.0% | — | 14.29% | A− |
| SkyWest Airlines | 844 | 79.6% | 92 min | 1.30% | B |
| Delta Air Lines (this page) | 443 | 78.0% | 103 min | 2.48% | B |
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 is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 443 flights.
- 5am–8am—
- 8am–11am22 flights—
- 11am–2pm—
- 2pm–5pm60 flights84.2%
- 5pm–8pm—
- 8pm–5am361 flights76.8%
Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 2pm–5pm slot at 84.2% on time, ahead of 8pm–5am at 76.8%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 8pm–5am window is the busiest, with 361 flights scheduled in it.
Across the year
Delta on DTW to BUF through the year
July is the worst month at 50.0% on time, 47 points below September, the best at 96.7%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. January was the busiest month here, with 56 flights.
Across the week, Thursday is the strongest day at 87.1% on time and Monday the weakest at 73.4%, a spread of 14 points.
Arrival by arrival
How late Delta on DTW to BUF runs when it is late
Delta on DTW to BUF often beats the schedule: 124 of 432 completed flights, 29%, arrived 15 minutes or more early. The 95 late arrivals split 24 under half an hour, 34 between 30 and 60 minutes, and 37 an hour or more.
- 15+ min early124 flights28.7%
- Within 15 min213 flights49.3%
- 15–29 min late24 flights5.6%
- 30–59 min late34 flights7.9%
- 1–2 hours late20 flights4.6%
- 2+ hours late17 flights3.9%
Scale runs 0% to 100%.
Share of 432 completed flights by arrival against schedule.
19 of 97 late departures made up the time and arrived on time, 20% of them. 17 flights left on time and still arrived late.
The worst days
Worst days for Delta on DTW to BUF
The latest arrival of the period was on 12 June 2026, 17 hours 21 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in December 2025.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 12 June 2026 | 17 hours 21 minutes | Carrier |
| 30 December 2025 | 16 hours 43 minutes | Carrier |
| 10 December 2025 | 16 hours 37 minutes | Carrier |
| 17 February 2026 | 10 hours 23 minutes | Extreme weather |
| 29 December 2025 | 9 hours 48 minutes | Carrier |
Delay causes
Why Delta runs late on this route
Carrier accounts for 64% of the 9,774 delay minutes carriers reported here, and the remaining four split what is left.
- 64%Carrier
- 19%Late-arriving aircraft
- 11%National Airspace System
- 7%Extreme weather
The largest share of delay minutes, 64%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 6,211 of the 9,774 delay minutes reported here. The split is drawn from 9,774 reported delay minutes.
Cancellations sit at 2.48% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
8.6% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last close to two hours, which a normal layover absorbs.
At 241 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 2pm–5pm window matters as much as it does.
The return leg is a different operation and performs like one: it runs 84.0% on time across 443 flights, 6 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 6 points of difference.
One caution: this is a thin sample. 443 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 DTW to BUF
Put together: treat all of this as provisional. 443 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 78.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 432 completed flights over 12 months sit behind that.
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.