Flight number record

DL 2351

Delta Air Lines · Dallas-Fort Worth to Boston

Route: DFW → BOS
Departs: 07:05
Flights: 348
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 2351, check with Delta Air Lines.

DL 2351 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 12 points better than the national rate of 77.6%. When something does go wrong the average delay runs close to two hours. That rests on 348 flights, with a median arrival 12 minutes early.

Set against the rest of the country, DL 2351's record is 12 points better than the US average of 77.6%. That gap is worth roughly 118 fewer late arrivals for every thousand flights.

On time

89.4%

Arrivals under 15 minutes late, of 339 completed flights

Avg delay

104 min

Across delayed arrivals only, not all flights

Cancelled

2.30%

National rate is 1.81%

1 hour+ late

4.4%

National rate is 8.1%

These figures cover 348 flights between July 2025 and June 2026. The median arrival is 12 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.

Schedule

When DL 2351 flies

DL 2351 flies DFW to BOS without a single fixed slot. Its most common scheduled departure was 07:05, used on 96 of 348 flights, with 07:00 (70 flights) and 07:20 (59 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 07:0596 flights27.6%
Departs 07:0070 flights20.1%
Departs 07:2059 flights17.0%

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 07:05 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 2351 runs level with that at 89.4%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

DL 2351 next to DFW to BOS

Every carrier on DFW to BOS combined arrived on time 67.1% of the time across 3,744 flights, so DL 2351 is 22 points ahead of it. Delta flew 861 flights on the same city pair under all its flight numbers, including this one, and those ran 77.4% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 8 points.

DL 2351 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 2351thin sample	348	89.4%	104 min	2.30%	A
All Delta Air Lines on DFW–BOS	861	77.4%	100 min	2.44%	B
All carriers on DFW–BOS	3,744	67.1%	76 min	3.21%	C−
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 2351 quarter by quarter

Quarter by quarter DL 2351 held fairly steady: 92.2% in Jul–Sep 2025, 90.0% in Oct–Dec 2025, 87.3% in Jan–Mar 2026 and 87.8% in Apr–Jun 2026. A spread of 5 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights92.2%
Oct–Dec 202580 flights90.0%
Jan–Mar 202685 flights87.3%
Apr–Jun 202691 flights87.8%

Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, DL 2351 ranged from 83.3% on Saturday to 91.8% on Thursday. With about 50 flights behind each day, a spread of 9 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why DL 2351 runs late

One category carries most of the weight here. Carrier accounts for 58% of the 3,749 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
58%
National Airspace System
17%
Extreme weather
13%
Late-arriving aircraft
12%

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 3,749 delay minutes reported on DL 2351.

Cancellations sit at 2.30% against a national 1.81%, which is ordinary. Diversions add another 0.29%.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 4.4% 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 1,562 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

Every one of the 348 flights under DL 2351 in the data flew DFW to BOS. The number was not reused on any other city pair, which makes this a clean record of one route.

One caution: this is a thin sample. 348 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 2351

For a booking, read DL 2351 as 89.4% on time with 2.30% cancelled over 348 flights. Those are rates from the past twelve months, not a forecast for any particular day.

Where to go next

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.

Key figures