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DelayAtlas

Flight number record

DL 1707

Delta Air Lines · Detroit to Boston

Route
DTW → BOS
Departs
17:59
Flights
268
Period
July 2025 to June 2026
D−GRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1707, check with Delta Air Lines.

DL 1707 earns a D−, which is as low as this site's scale goes for a reason. Only 56.8% of flights arrive inside the 15-minute window, 21 points worse than the national rate of 77.6%. Late arrivals average a little over an hour. Treat any tight connection here as a coin flip. That rests on 268 flights, with a median arrival 10 minutes late.

The national on-time rate over the same period is 77.6%, so DL 1707 runs 21 points behind the country as a whole. Across a thousand flights that is about 208 extra late arrivals.

Key figures

On time

56.8%

Arrivals under 15 minutes late, of 259 completed flights

Avg delay

68 min

Across delayed arrivals only, not all flights

Cancelled

3.36%

National rate is 1.81%

1 hour+ late

18.9%

National rate is 8.1%

These figures cover 268 flights between July 2025 and June 2026. Beyond the headline rate, 18.9% 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 1707 flies

DL 1707 flies DTW to BOS without a single fixed slot. Its most common scheduled departure was 17:59, used on 80 of 268 flights, with 17:40 (55 flights) and 17:56 (50 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

  • Departs 17:5980 flights29.9%
  • Departs 17:4055 flights20.5%
  • Departs 17:5650 flights18.7%

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 17:59 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and DL 1707 runs 11 points worse at 56.8%. 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 1707 next to DTW to BOS

Every carrier on DTW to BOS combined arrived on time 74.8% of the time across 2,588 flights, so DL 1707 is 18 points behind it. Delta flew 1,710 flights on the same city pair under all its flight numbers, including this one, and those ran 74.9% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 25 points.

DL 1707 against its route and carrier
Compared withFlightsOn timeAvg delayCancelledGrade
DL 1707thin sample26856.8%68 min3.36%D−
All Delta Air Lines on DTW–BOS1,71074.9%67 min1.81%C
All carriers on DTW–BOS2,58874.8%72 min2.09%C
Delta Air Lines, whole network1,038,57081.6%71 min1.62%B

Across the year

DL 1707 quarter by quarter

DL 1707 did not run the same all year. Its best quarter was Jan–Mar 2026 at 68.1% on time and its weakest Jul–Sep 2025 at 44.3%, a swing of 24 points on roughly 67 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 202571 flights44.3%
  • Oct–Dec 202571 flights61.4%
  • Jan–Mar 202651 flights68.1%
  • Apr–Jun 202675 flights56.9%

Scale runs 35% to 75%. Rows with fewer than 30 flights show a dash.

By weekday, DL 1707 did best on Monday at 69.0% on time and worst on Wednesday at 45.9%. Each day rests on about 38 flights, so a gap of 23 points is worth noticing but could still narrow in another year.

On-time rate by day of the week69.0Mon54.1Tue45.9Wed55.6Thu55.8FriSat53.7Sun
Monday: 69.0 percent on time. Tuesday: 54.1 percent on time. Wednesday: 45.9 percent on time. Thursday: 55.6 percent on time. Friday: 55.8 percent on time. Saturday: not enough flights. Sunday: 53.7 percent on time

Delay causes

Why DL 1707 runs late

One category carries most of the weight here. National Airspace System accounts for 57% of the 7,642 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.

  • National Airspace System
    57%
  • Carrier
    30%
  • Late-arriving aircraft
    11%
  • Extreme weather
    1%

57% 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 4,356 minutes out of 7,642, against a national NAS share of 21%. The split is drawn from 7,642 delay minutes reported on DL 1707.

Cancellations run at 3.36%, 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. 18.9% 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 632 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 ATL to BOS (5), but none flew often enough under DL 1707 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DTW to BOS only.

One caution: this is a thin sample. 268 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 1707

For a booking, the cancellation rate is the figure to plan around on DL 1707: 3.36% of its 268 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

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.