Carrier route record

DLBOS→MSY

Delta Air Lines · Boston to New Orleans

Flights: 374
Period: July 2025 to June 2026
Share of route: 44%
Carriers: 4

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

Delta on BOS to MSY earns a B. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 374 flights, with a median arrival 8 minutes early.

Set against the rest of the country, Delta's BOS to MSY record is 7 points better than the US average of 77.6%. That gap is worth roughly 65 fewer late arrivals for every thousand flights.

On time

84.1%

Arrivals under 15 minutes late, of 365 completed flights

Avg delay

59 min

Across delayed arrivals only, not all flights

Cancelled

2.14%

National rate is 1.81%

Whole route

76.6%

Every carrier on BOS to MSY, 855 flights

These figures cover 374 flights between July 2025 and June 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.

Carrier by carrier

Delta against every carrier on BOS to MSY

Delta flew 374 of the 855 flights on BOS to MSY, about 44% of it. Its 84.1% on time is 8 points better than the route as a whole, which runs 76.6%. Ranked by on-time rate it is first of four carriers on the route, where the range runs from Delta at 84.1% to American 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.

On-time performance by carrier on BOS to MSY
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines (this page)	374	84.1%	59 min	2.14%	B
JetBlue Airways	471	71.0%	84 min	1.06%	C
Spirit Airlinesthin sample	8	62.5%	45 min	0.00%	D+
American Airlinesthin sample	2	50.0%	54 min	0.00%	F+

Flight by flight

Delta flight numbers on BOS to MSY

DL 139811:1083.9% · 364 flights

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 374 flights.

There are not enough flights in each departure window to split Delta's BOS to MSY record by time of day without the percentages moving on noise. The headline rate of 84.1% is the reliable figure here.

Across the year

Delta on BOS to MSY through the year

Darker means more delays. Figures are on-time percentages.March best, December worst

December is the weak month at 70.0% on time, against 93.3% in March. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. April was the busiest month here, with 35 flights.

Across the week, Sunday is the strongest day at 90.0% on time and Thursday the weakest at 79.2%. 11 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Carrier accounts for 45% of the 3,440 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
45%
National Airspace System
29%
Late-arriving aircraft
25%
Extreme weather
1%

The largest share of delay minutes, 45%, 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 1,561 of the 3,440 delay minutes reported here. The split is drawn from 3,440 reported delay minutes.

Cancellations sit at 2.14% against a national 1.81%, which is ordinary. Diversions add another 0.27%.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 3.3% 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 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. 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 return leg is a different operation and performs like one: it runs 63.7% on time across 372 flights, 20 points below 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. 374 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 BOS to MSY

Put together: treat all of this as provisional. 374 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 84.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 365 completed flights over 12 months sit behind that.

Where to go next

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