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DelayAtlas

Carrier route record

DLBOSJFK

Delta Air Lines · Boston to New York

Flights
368
Period
July 2025 to June 2026
Share of route
6%
Carriers
3
AGRADE

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

Delta on BOS to JFK earns an A. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 13 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 368 flights. The strongest carrier on the route with a full sample, Republic Airways, flew 2,915 at 75.1% on time.

Set against the rest of the country, Delta's BOS to JFK record is 13 points better than the US average of 77.6%. That gap is worth roughly 132 fewer late arrivals for every thousand flights.

Key figures

On time

90.8%

Arrivals under 15 minutes late, of 357 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

2.99%

National rate is 1.81%

Whole route

75.5%

Every carrier on BOS to JFK, 5,738 flights

These figures cover 368 flights between July 2025 and June 2026. The median arrival is 14 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 JFK

Delta flew 368 of the 5,738 flights on BOS to JFK, about 6% of it. Its 90.8% on time is 15 points better than the route as a whole, which runs 75.5%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Delta at 90.8% to JetBlue at 73.6%.

The two carriers here are closely matched: 2 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on BOS to JFK
AirlineFlightsOn timeAvg delayCancelledGrade
Delta Air Lines (this page)36890.8%63 min2.99%A
Republic Airways2,91575.1%66 min5.01%B−
JetBlue Airways2,45573.6%81 min4.24%C−

Republic Airways cancels 5.0% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

Flight by flight

Delta flight numbers on BOS to JFK

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 368 flights.

There are not enough flights in each departure window to split Delta's BOS to JFK record by time of day without the percentages moving on noise. The headline rate of 90.8% is the reliable figure here.

Across the year

Delta on BOS to JFK through the year

On-time rate by calendar monthJF97M97A100MJJ94A90S80O100N80D
Darker means more delays. Figures are on-time percentages.May best, October worst

December is the weak month at 80.0% on time, against 100.0% in May. 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 32 flights.

Across the week, Thursday is the strongest day at 94.2% on time and Monday the weakest at 87.8%. 6 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week87.8Mon88.2Tue90.2Wed94.2Thu91.8Fri88.7Sat94.2Sun
Monday: 87.8 percent on time. Tuesday: 88.2 percent on time. Wednesday: 90.2 percent on time. Thursday: 94.2 percent on time. Friday: 91.8 percent on time. Saturday: 88.7 percent on time. Sunday: 94.2 percent on time

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Carrier accounts for 56% of the 2,083 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
    56%
  • Late-arriving aircraft
    26%
  • National Airspace System
    17%
  • Extreme weather
    1%

The largest share of delay minutes, 56%, 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 1,156 of the 2,083 delay minutes reported here. The split is drawn from 2,083 reported delay minutes.

Cancellations run at 2.99%, against 1.81% nationally. That is roughly 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 stage length

What a delay here costs

Badly late arrivals are rare here: only 2.8% 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.

At 187 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 68.8% on time across 368 flights, 22 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 22 points of difference.

One caution: this is a thin sample. 368 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 JFK

Put together: the delay figures matter less here than the 2.99% cancellation rate. A late arrival costs you about an hour; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 357 completed flights over 12 months sit behind that.

Related

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.