Flight number record
DL 455
Delta Air Lines · Washington to Atlanta
- Route
- DCA → ATL
- Departs
- 09:00
- Flights
- 344
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 455, check with Delta Air Lines.
DL 455 lands a B, 6 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by close to two hours on average. That rests on 344 flights, with a median arrival 8 minutes early.
Set against the rest of the country, DL 455's record is 6 points better than the US average of 77.3%. That gap is worth roughly 60 fewer late arrivals for every thousand flights.
Key figures
On time
83.3%
Arrivals under 15 minutes late, of 335 completed flights
Avg delay
120 min
Across delayed arrivals only, not all flights
Cancelled
2.62%
National rate is 1.89%
1 hour+ late
5.7%
National rate is 8.3%
These figures cover 344 flights between September 2025 and August 2026. The median arrival is 8 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 455 flies
DL 455 flies DCA to ATL without a single fixed slot. Its most common scheduled departure was 09:00, used on 214 of 344 flights, with 08:59 (114 flights) next.
- Departs 09:00214 flights62.2%
- Departs 08:59114 flights33.1%
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 09:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and DL 455 runs level with that at 83.3%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
DL 455 next to DCA to ATL
Every carrier on DCA to ATL combined arrived on time 77.1% of the time across 6,799 flights, so DL 455 is 6 points ahead of it. Delta flew 3,850 flights on the same city pair under all its flight numbers, including this one, and those ran 79.2% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 2 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 455thin sample | 344 | 83.3% | 120 min | 2.62% | B |
| All Delta Air Lines on DCA–ATL | 3,850 | 79.2% | 88 min | 2.55% | B |
| All carriers on DCA–ATL | 6,799 | 77.1% | 79 min | 3.60% | B− |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 455 quarter by quarter
DL 455 did not run the same all year. Its best quarter was Apr–Jun 2026 at 87.9% on time and its weakest Jul–Sep 2026 at 67.2%, a swing of 21 points on roughly 69 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 flights86.7%
- Oct–Dec 202572 flights86.1%
- Jan–Mar 202690 flights85.7%
- Apr–Jun 202691 flights87.9%
- Jul–Sep 202661 flights67.2%
Scale runs 60% to 95%.
By weekday, DL 455 did best on Saturday at 91.8% on time and worst on Friday at 72.9%. Each day rests on about 49 flights, so a gap of 19 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 455 runs when it is late
DL 455 often beats the schedule: 117 of 335 completed flights, 35%, arrived 15 minutes or more early. The 56 late arrivals split 19 under half an hour, 18 between 30 and 60 minutes, and 19 an hour or more.
- 15+ min early117 flights34.9%
- Within 15 min162 flights48.4%
- 15–29 min late19 flights5.7%
- 30–59 min late18 flights5.4%
- 1–2 hours late7 flights2.1%
- 2+ hours late12 flights3.6%
Scale runs 0% to 100%.
Share of 335 completed flights by arrival against schedule.
14 of 57 late departures made up the time and arrived on time, 25% of them. 13 flights left on time and still arrived late.
The worst days
Worst days for DL 455
The latest arrival of the period was on 11 February 2026, 13 hours 37 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 11 February 2026 | 13 hours 37 minutes | Carrier |
| 12 June 2026 | 12 hours 38 minutes | Extreme weather |
| 12 August 2026 | 12 hours 6 minutes | Carrier |
| 14 May 2026 | 12 hours 1 minute | Carrier |
| 3 August 2026 | 7 hours 52 minutes | Carrier |
Delay causes
Why DL 455 runs late
Carrier accounts for 78% of the 6,705 delay minutes carriers reported here, and the remaining four split what is left.
- 78%Carrier
- 13%Extreme weather
- 9%National Airspace System
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 6,705 delay minutes reported on DL 455.
Cancellations run at 2.62%, against 1.89% 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
5.7% 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 close to two 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.
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. 344 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: 2.62% of its 344 scheduled flights did not operate. A late arrival costs close to two hours, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- DCA to ATL, every carrier and departure
- ATL to DCA, the return direction
- Delta Air Lines 926 on the same route86.5%
- Delta Air Lines 380 on the same route77.2%
- Delta Air Lines 410 on the same route94.1%
- Delta Air Lines 850 on the same route63.4%
- Delta Air Lines 330 on the same route93.1%
- Delta Air Lines 360 on the same route69.3%
- Ronald Reagan Washington National (DCA) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) 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.