Flight number record
DL 2570
Delta Air Lines · Boston to Chicago
- Route
- BOS → ORD
- Departs
- 07:20
- Flights
- 260
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s DL 2570, check with Delta Air Lines.
DL 2570 lands a B−, 2 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 260 flights, with a median arrival 7 minutes early.
Key figures
On time
80.0%
Arrivals under 15 minutes late, of 250 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
3.46%
National rate is 1.81%
1 hour+ late
6.0%
National rate is 8.1%
These figures cover 260 flights between July 2025 and June 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.
Schedule
When DL 2570 flies
DL 2570 flies BOS to ORD without a single fixed slot. Its most common scheduled departure was 07:20, used on 91 of 260 flights, with 07:30 (63 flights) and 07:25 (31 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 07:2091 flights35.0%
- Departs 07:3063 flights24.2%
- Departs 07:2531 flights11.9%
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 07:20 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 80.0%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
Against the route
DL 2570 next to BOS to ORD
Every carrier on BOS to ORD combined arrived on time 72.7% of the time across 7,637 flights, so DL 2570 is 7 points ahead of it. Delta flew 962 flights on the same city pair under all its flight numbers, including this one, and those ran 65.2% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 2 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 2570thin sample | 260 | 80.0% | 64 min | 3.46% | B− |
| All Delta Air Lines on BOS–ORD | 962 | 65.2% | 75 min | 3.12% | C− |
| All carriers on BOS–ORD | 7,637 | 72.7% | 84 min | 2.91% | C |
| Delta Air Lines, whole network | 1,038,570 | 81.6% | 71 min | 1.62% | 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 87 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 202585 flights83.3%
- Oct–Dec 202580 flights67.1%
- Jan–Mar 202621 flights—
- Apr–Jun 202674 flights88.7%
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
By weekday, DL 2570 did best on Thursday at 91.9% on time and worst on Sunday at 70.0%. Each day rests on about 37 flights, so a gap of 22 points is worth noticing but could still narrow in another year.
Delay causes
Why DL 2570 runs late
One category carries most of the weight here. Carrier accounts for 60% of the 3,173 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 60%Carrier
- 36%National Airspace System
- 4%Late-arriving aircraft
The largest share of delay minutes, 60%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 1,893 of the 3,173 delay minutes reported here. The split is drawn from 3,173 delay minutes reported on DL 2570.
Cancellations run at 3.46%, 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
6.0% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The same number turns up on one other city pair in the data, including ORD to BOS (235), 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. 260 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: 3.46% of its 260 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 route52.3%
- United Airlines 1732 on the same route84.5%
- United Airlines 1414 on the same route94.2%
- United Airlines 1015 on the same route48.8%
- JetBlue Airways 311 on the same route84.3%
- Delta Air Lines 2646 on the same route60.3%
- 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.