Flight number record
DL 2570
Delta Air Lines · Boston to Chicago
- Route
- BOS → ORD
- Departs
- 07:30
- Flights
- 266
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 2570, check with Delta Air Lines.
DL 2570 lands a B−, 3 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 266 flights, with a median arrival 7 minutes early.
Key figures
On time
80.5%
Arrivals under 15 minutes late, of 257 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
3.01%
National rate is 1.89%
1 hour+ late
5.4%
National rate is 8.3%
These figures cover 266 flights between September 2025 and August 2026. The median arrival is 7 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 2570 flies
DL 2570 flies BOS to ORD without a single fixed slot. Its most common scheduled departure was 07:30, used on 124 of 266 flights, with 07:20 (42 flights) and 07:25 (31 flights) next.
- Departs 07:30124 flights46.6%
- Departs 07:2042 flights15.8%
- Departs 07:2531 flights11.7%
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 07:30 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 2570 runs 9 points worse at 80.5%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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.
Against the route
DL 2570 next to BOS to ORD
Every carrier on BOS to ORD combined arrived on time 71.9% of the time across 7,860 flights, so DL 2570 is 9 points ahead of it. Delta flew 981 flights on the same city pair under all its flight numbers, including this one, and those ran 63.7% on time. Across its whole network Delta Air Lines managed 81.1%, close to this flight's figure.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 2570thin sample | 266 | 80.5% | 58 min | 3.01% | B− |
| All Delta Air Lines on BOS–ORD | 981 | 63.7% | 75 min | 3.47% | D− |
| All carriers on BOS–ORD | 7,860 | 71.9% | 87 min | 2.98% | C |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 2570 quarter by quarter
DL 2570 did not run the same all year. Its best quarter was Apr–Jun 2026 at 88.7% on time and its weakest Oct–Dec 2025 at 67.1%, a swing of 22 points on roughly 67 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 flights80.0%
- Oct–Dec 202580 flights67.1%
- Jan–Mar 202621 flights—
- Apr–Jun 202674 flights88.7%
- Jul–Sep 202661 flights86.9%
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
By weekday, DL 2570 did best on Thursday at 92.1% on time and worst on Sunday at 75.0%. Each day rests on about 38 flights, so a gap of 17 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 2570 runs when it is late
DL 2570 often beats the schedule: 84 of 257 completed flights, 33%, arrived 15 minutes or more early. Most of the lateness is short. 25 of the 50 late arrivals were under half an hour behind, and 14 reached an hour or more.
- 15+ min early84 flights32.7%
- Within 15 min123 flights47.9%
- 15–29 min late25 flights9.7%
- 30–59 min late11 flights4.3%
- 1–2 hours late10 flights3.9%
- 2+ hours late4 flights1.6%
Scale runs 0% to 100%.
Share of 257 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 27 departures that left 15 minutes late or more, only 2 made it up before arrival. 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 DL 2570
The latest arrival of the period was on 20 September 2025, 6 hours 2 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 20 September 2025 | 6 hours 2 minutes | Carrier |
| 13 September 2025 | 4 hours 58 minutes | National Airspace System |
| 3 August 2026 | 2 hours 43 minutes | National Airspace System |
| 2 November 2025 | 2 hours 21 minutes | Carrier |
| 1 December 2025 | 1 hour 54 minutes | Carrier |
Delay causes
Why DL 2570 runs late
National Airspace System accounts for 50% of the 2,891 delay minutes carriers reported here, and the remaining four split what is left.
- 50%National Airspace System
- 45%Carrier
- 4%Late-arriving aircraft
The largest share of delay minutes, 45%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,309 of the 2,891 delay minutes reported here. The split is drawn from 2,891 delay minutes reported on DL 2570.
Cancellations run at 3.01%, against 1.89% nationally. That is roughly 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
5.4% 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 about an hour, which a normal layover absorbs.
The 867 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.
The same number turns up on one other city pair in the data, including ORD to BOS (242), but none flew often enough under DL 2570 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to BOS to ORD only.
One caution: this is a thin sample. 266 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 2570
For a booking, the cancellation rate is the figure to plan around on DL 2570: 3.01% of its 266 scheduled flights did not operate. A late arrival costs about an hour, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- BOS to ORD, every carrier and departure
- ORD to BOS, the return direction
- United Airlines 2040 on the same route53.1%
- United Airlines 1414 on the same route93.6%
- United Airlines 1732 on the same route83.8%
- United Airlines 1349 on the same route86.0%
- United Airlines 1015 on the same route50.3%
- JetBlue Airways 311 on the same route79.1%
- Boston Logan International (BOS) 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.