Flight number record

DL 865

Delta Air Lines · Atlanta to Boston

Route: ATL → BOS
Departs: 22:40
Flights: 360
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 865, check with Delta Air Lines.

DL 865 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 a little over an hour on average. That is a workable record, not a spotless one. That rests on 360 flights, with a median arrival 10 minutes early.

On time

79.8%

Arrivals under 15 minutes late, of 351 completed flights

Avg delay

77 min

Across delayed arrivals only, not all flights

Cancelled

2.50%

National rate is 1.81%

1 hour+ late

6.6%

National rate is 8.1%

These figures cover 360 flights between July 2025 and June 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.

Schedule

When DL 865 flies

DL 865 flies ATL to BOS without a single fixed slot. Its most common scheduled departure was 22:40, used on 114 of 360 flights, with 22:35 (55 flights) and 22:50 (54 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 22:40114 flights31.7%
Departs 22:3555 flights15.3%
Departs 22:5054 flights15.0%

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 22:40 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.5%, and DL 865 runs 9 points better at 79.8%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

DL 865 next to ATL to BOS

Every carrier on ATL to BOS combined arrived on time 74.5% of the time across 4,935 flights, so DL 865 is 5 points ahead of it. Delta flew 3,666 flights on the same city pair under all its flight numbers, including this one, and those ran 76.2% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 2 points.

DL 865 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 865thin sample	360	79.8%	77 min	2.50%	B
All Delta Air Lines on ATL–BOS	3,666	76.2%	59 min	1.72%	B
All carriers on ATL–BOS	4,935	74.5%	63 min	1.95%	C
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 865 quarter by quarter

Quarter by quarter DL 865 held fairly steady: 79.3% in Jul–Sep 2025, 77.4% in Oct–Dec 2025, 77.6% in Jan–Mar 2026 and 84.4% in Apr–Jun 2026. A spread of 7 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights79.3%
Oct–Dec 202587 flights77.4%
Jan–Mar 202690 flights77.6%
Apr–Jun 202691 flights84.4%

Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, DL 865 ranged from 72.5% on Thursday to 84.3% on Saturday. With about 51 flights behind each day, a spread of 12 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why DL 865 runs late

One category carries most of the weight here. Carrier accounts for 46% of the 5,439 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.

Carrier
46%
Late-arriving aircraft
28%
Extreme weather
20%
National Airspace System
6%

Extreme weather accounts for 20% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 3.2 times the usual weather exposure. The split is drawn from 5,439 delay minutes reported on DL 865.

Cancellations run at 2.50%, against 1.81% nationally. That is about one flight in 40 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

6.6% 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 a little over an hour, which a normal layover absorbs.

The 946 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.

Every one of the 360 flights under DL 865 in the data flew ATL to BOS. 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. 360 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 865

For a booking, the cancellation rate is the figure to plan around on DL 865: 2.50% of its 360 scheduled flights did not operate. A late arrival costs a little over an hour, but a cancellation costs the day, so leave a later option open.

Where to go next

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.

Key figures