Carrier route record
DLMSY→BOS
Delta Air Lines · New Orleans to Boston
- Flights
- 372
- Period
- September 2025 to August 2026
- Share of route
- 43%
- Carriers
- 4
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on MSY to BOS draws a D. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is an hour and a half behind schedule. Build slack into anything you connect to. That rests on 372 flights, with a median arrival 3 minutes late.
The national on-time rate over the same period is 77.3%, so Delta on MSY to BOS runs 14 points behind the country as a whole. Across a thousand flights that is about 144 extra late arrivals.
Key figures
On time
62.9%
Arrivals under 15 minutes late, of 364 completed flights
Avg delay
83 min
Across delayed arrivals only, not all flights
Cancelled
2.15%
National rate is 1.89%
Whole route
61.9%
Every carrier on MSY to BOS, 861 flights
These figures cover 372 flights between September 2025 and August 2026. Beyond the headline rate, 17.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Delta against every carrier on MSY to BOS
Delta flew 372 of the 861 flights on MSY to BOS, about 43% of it. Its 62.9% on time is about level with the route as a whole at 61.9%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from American at 100.0% to Spirit at 50.0%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlinesthin sample | 2 | 100.0% | — | 0.00% | A+ |
| Delta Air Lines (this page) | 372 | 62.9% | 83 min | 2.15% | D |
| JetBlue Airways | 479 | 61.2% | 87 min | 2.09% | D |
| Spirit Airlinesthin sample | 8 | 50.0% | 39 min | 0.00% | F+ |
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Departure window
When Delta runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 372 flights.
There are not enough flights in each departure window to split Delta's MSY to BOS record by time of day without the percentages moving on noise. The headline rate of 62.9% is the reliable figure here.
Across the year
Delta on MSY to BOS through the year
Delays peak in October, when the on-time rate falls to 48.5%. December is the strongest month at 83.3%. Moving a flexible trip across that boundary buys 35 points. April was the busiest month here, with 35 flights.
Across the week, Saturday is the strongest day at 70.4% on time and Thursday the weakest at 56.9%, a spread of 14 points.
Arrival by arrival
How late Delta on MSY to BOS runs when it is late
The 135 late arrivals split 40 under half an hour, 33 between 30 and 60 minutes, and 62 an hour or more.
- 15+ min early76 flights20.9%
- Within 15 min153 flights42.0%
- 15–29 min late40 flights11.0%
- 30–59 min late33 flights9.1%
- 1–2 hours late33 flights9.1%
- 2+ hours late29 flights8.0%
Scale runs 0% to 100%.
Share of 364 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 118 departures that left 15 minutes late or more, only 14 made it up before arrival. In the other direction, 31 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at BOS.
The worst days
Worst days for Delta on MSY to BOS
The latest arrival of the period was on 3 December 2025, 13 hours 40 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across December, July, August, October and September, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 3 December 2025 | 13 hours 40 minutes | Carrier |
| 7 July 2026 | 5 hours 7 minutes | National Airspace System |
| 10 August 2026 | 4 hours 35 minutes | Late-arriving aircraft |
| 14 October 2025 | 4 hours 5 minutes | National Airspace System |
| 6 September 2025 | 3 hours 53 minutes | Late-arriving aircraft |
Delay causes
Why Delta runs late on this route
National Airspace System accounts for 52% of the 11,000 delay minutes carriers reported here, and the remaining four split what is left.
- 52%National Airspace System
- 31%Late-arriving aircraft
- 14%Carrier
- 4%Extreme weather
- 0%Security
52% 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 5,763 minutes out of 11,000, against a national NAS share of 21%. The split is drawn from 11,132 reported delay minutes.
Cancellations sit at 2.15% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
17.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The 1,367 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 return leg is a different operation and performs like one: it runs 82.7% on time across 374 flights, 20 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 20 points of difference.
One caution: this is a thin sample. 372 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 Delta on MSY to BOS
Put together: treat all of this as provisional. 372 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 62.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 364 completed flights over 12 months sit behind that.
Related
Where to go next
- MSY to BOS, every carrier
- Delta on BOS to MSY, the return leg
- JetBlue Airways on MSY to BOS61.2%
- Delta Air Lines network-wide record
- Louis Armstrong New Orleans International (MSY) delay statistics
- Boston Logan International (BOS) delay statistics
- How often a connection fails at the major US hubs
- Worst months to fly in the US, ranked by the data
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.