Flight number record

DL 456

Delta Air Lines · Boston to Atlanta

Route: BOS → ATL
Departs: 08:05
Flights: 359
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 456, check with Delta Air Lines.

DL 456 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 11 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 359 flights, with a median arrival 11 minutes early.

Set against the rest of the country, DL 456's record is 11 points better than the US average of 77.6%. That gap is worth roughly 113 fewer late arrivals for every thousand flights.

On time

88.9%

Arrivals under 15 minutes late, of 350 completed flights

Avg delay

97 min

Across delayed arrivals only, not all flights

Cancelled

2.23%

National rate is 1.81%

1 hour+ late

3.7%

National rate is 8.1%

These figures cover 359 flights between July 2025 and June 2026. The median arrival is 11 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 456 flies

DL 456 flies BOS to ATL without a single fixed slot. Its most common scheduled departure was 08:05, used on 84 of 359 flights, with 09:05 (84 flights) and 08:30 (60 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 08:0584 flights23.4%
Departs 09:0584 flights23.4%
Departs 08:3060 flights16.7%

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 08:05 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and DL 456 runs 5 points better at 88.9%. 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 456 next to BOS to ATL

Every carrier on BOS to ATL combined arrived on time 78.5% of the time across 4,931 flights, so DL 456 is 10 points ahead of it. Delta flew 3,662 flights on the same city pair under all its flight numbers, including this one, and those ran 82.1% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 7 points.

DL 456 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 456thin sample	359	88.9%	97 min	2.23%	A
All Delta Air Lines on BOS–ATL	3,662	82.1%	75 min	1.77%	B
All carriers on BOS–ATL	4,931	78.5%	69 min	1.99%	B
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 456 quarter by quarter

DL 456 did not run the same all year. Its best quarter was Apr–Jun 2026 at 95.6% on time and its weakest Jan–Mar 2026 at 83.3%, a swing of 12 points on roughly 90 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 202592 flights89.1%
Oct–Dec 202586 flights86.9%
Jan–Mar 202690 flights83.3%
Apr–Jun 202691 flights95.6%

Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, DL 456 did best on Thursday at 96.2% on time and worst on Sunday at 80.8%. Each day rests on about 51 flights, so a gap of 15 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 456 runs late

One category carries most of the weight here. Carrier accounts for 54% of the 3,774 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
54%
National Airspace System
24%
Late-arriving aircraft
20%
Extreme weather
2%

The largest share of delay minutes, 54%, 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 2,033 of the 3,774 delay minutes reported here. The split is drawn from 3,774 delay minutes reported on DL 456.

Cancellations sit at 2.23% against a national 1.81%, which is ordinary. Diversions add another 0.28%.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 3.7% land an hour or more behind schedule, against 8.1% 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 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 359 flights under DL 456 in the data flew BOS to ATL. 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. 359 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 456

For a booking, read DL 456 as 88.9% on time with 2.23% cancelled over 359 flights. Those are rates from the past twelve months, not a forecast for any particular day.

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