Flight number record
DL 434
Delta Air Lines · Atlanta to New York
- Route
- ATL → LGA
- Departs
- 18:00
- Flights
- 343
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s DL 434, check with Delta Air Lines.
DL 434 draws a D−. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 343 flights, with a median arrival 3 minutes late.
The national on-time rate over the same period is 77.6%, so DL 434 runs 15 points behind the country as a whole. Across a thousand flights that is about 154 extra late arrivals.
Key figures
On time
62.2%
Arrivals under 15 minutes late, of 331 completed flights
Avg delay
75 min
Across delayed arrivals only, not all flights
Cancelled
3.21%
National rate is 1.81%
1 hour+ late
17.2%
National rate is 8.1%
These figures cover 343 flights between July 2025 and June 2026. Beyond the headline rate, 17.2% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Schedule
When DL 434 flies
DL 434 flies ATL to LGA without a single fixed slot. Its most common scheduled departure was 18:00, used on 126 of 343 flights, with 19:30 (104 flights) and 19:00 (100 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 18:00126 flights36.7%
- Departs 19:30104 flights30.3%
- Departs 19:00100 flights29.2%
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 18:00 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and DL 434 runs 6 points worse at 62.2%. 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 434 next to ATL to LGA
Every carrier on ATL to LGA combined arrived on time 73.4% of the time across 8,344 flights, so DL 434 is 11 points behind it. Delta flew 4,936 flights on the same city pair under all its flight numbers, including this one, and those ran 76.7% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 19 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 434thin sample | 343 | 62.2% | 75 min | 3.21% | D− |
| All Delta Air Lines on ATL–LGA | 4,936 | 76.7% | 66 min | 2.96% | B |
| All carriers on ATL–LGA | 8,344 | 73.4% | 75 min | 3.61% | C− |
| Delta Air Lines, whole network | 1,038,570 | 81.6% | 71 min | 1.62% | B |
Across the year
DL 434 quarter by quarter
DL 434 did not run the same all year. Its best quarter was Jan–Mar 2026 at 69.6% on time and its weakest Oct–Dec 2025 at 58.0%, a swing of 12 points on roughly 86 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 202586 flights61.4%
- Oct–Dec 202591 flights58.0%
- Jan–Mar 202683 flights69.6%
- Apr–Jun 202683 flights60.5%
Scale runs 50% to 75%. Rows with fewer than 30 flights show a dash.
By weekday, DL 434 did best on Wednesday at 70.6% on time and worst on Sunday at 44.9%. Each day rests on about 49 flights, so a gap of 26 points is worth noticing but could still narrow in another year.
Delay causes
Why DL 434 runs late
One category carries most of the weight here. National Airspace System accounts for 53% of the 9,358 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.
- 53%National Airspace System
- 26%Carrier
- 17%Late-arriving aircraft
- 3%Extreme weather
- 0%Security
53% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 4,977 minutes out of 9,358, against a national NAS share of 21%. The split is drawn from 9,358 delay minutes reported on DL 434.
Cancellations run at 3.21%, 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
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 17.2% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
The 762 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 LGA (5), but none flew often enough under DL 434 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to ATL to LGA only.
One caution: this is a thin sample. 343 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 434
For a booking, the cancellation rate is the figure to plan around on DL 434: 3.21% of its 343 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.
Related
Where to go next
- ATL to LGA, every carrier and departure
- LGA to ATL, the return direction
- Delta Air Lines 520 on the same route70.4%
- Frontier Airlines 3288 on the same route40.8%
- Delta Air Lines 997 on the same route66.2%
- Delta Air Lines 513 on the same route88.6%
- Delta Air Lines 371 on the same route85.5%
- Delta Air Lines 557 on the same route86.7%
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- LaGuardia (LGA) 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
- How often a connection fails at the major US hubs
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.