Flight number record

DL 455

Delta Air Lines · Washington to Atlanta

Route: DCA → ATL
Departs: 09:00
Flights: 345
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 455, check with Delta Air Lines.

DL 455 earns an A. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 2.3 hours. That rests on 345 flights, with a median arrival 9 minutes early.

Set against the rest of the country, DL 455's record is 8 points better than the US average of 77.6%. That gap is worth roughly 78 fewer late arrivals for every thousand flights.

On time

85.4%

Arrivals under 15 minutes late, of 336 completed flights

Avg delay

137 min

Across delayed arrivals only, not all flights

Cancelled

2.61%

National rate is 1.81%

1 hour+ late

6.2%

National rate is 8.1%

These figures cover 345 flights between July 2025 and June 2026. The median arrival is 9 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 455 flies

DL 455 flies DCA to ATL without a single fixed slot. Its most common scheduled departure was 09:00, used on 172 of 345 flights, with 08:59 (157 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 09:00172 flights49.9%
Departs 08:59157 flights45.5%

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 09:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and DL 455 runs level with that at 85.4%. 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 455 next to DCA to ATL

Every carrier on DCA to ATL combined arrived on time 78.8% of the time across 6,813 flights, so DL 455 is 7 points ahead of it. Delta flew 3,838 flights on the same city pair under all its flight numbers, including this one, and those ran 80.9% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 4 points.

DL 455 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 455thin sample	345	85.4%	137 min	2.61%	A
All Delta Air Lines on DCA–ATL	3,838	80.9%	88 min	2.81%	B
All carriers on DCA–ATL	6,813	78.8%	80 min	3.54%	B−
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 455 quarter by quarter

Quarter by quarter DL 455 held fairly steady: 82.0% in Jul–Sep 2025, 86.1% in Oct–Dec 2025, 85.7% in Jan–Mar 2026 and 87.9% in Apr–Jun 2026. A spread of 6 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights82.0%
Oct–Dec 202572 flights86.1%
Jan–Mar 202690 flights85.7%
Apr–Jun 202691 flights87.9%

Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, DL 455 ranged from 80.9% on Friday to 91.8% on Saturday. With about 49 flights behind each day, a spread of 11 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why DL 455 runs late

One category carries most of the weight here. Carrier accounts for 79% of the 6,707 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
79%
Extreme weather
13%
National Airspace System
5%
Late-arriving aircraft
3%

Extreme weather accounts for 13% 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 2.1 times the usual weather exposure. The split is drawn from 6,707 delay minutes reported on DL 455.

Cancellations run at 2.61%, 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

6.2% 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 2.3 hours, which a normal layover absorbs.

The 547 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 JFK to DTW (18), but none flew often enough under DL 455 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DCA to ATL only.

One caution: this is a thin sample. 345 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 455

For a booking, the cancellation rate is the figure to plan around on DL 455: 2.61% of its 345 scheduled flights did not operate. A late arrival costs about 2.3 hours, 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