Flight number record

DL 1677

Delta Air Lines · Boston to Austin

Route: BOS → AUS
Departs: 17:45
Flights: 344
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1677, check with Delta Air Lines.

DL 1677 draws a D−. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is close to two hours behind schedule. Build slack into anything you connect to. That rests on 344 flights, with a median arrival 1 minute early.

The national on-time rate over the same period is 77.6%, so DL 1677 runs 15 points behind the country as a whole. Across a thousand flights that is about 147 extra late arrivals.

On time

62.9%

Arrivals under 15 minutes late, of 329 completed flights

Avg delay

113 min

Across delayed arrivals only, not all flights

Cancelled

4.07%

National rate is 1.81%

1 hour+ late

17.3%

National rate is 8.1%

These figures cover 344 flights between July 2025 and June 2026. Beyond the headline rate, 17.3% 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 1677 flies

DL 1677 flies BOS to AUS without a single fixed slot. Its most common scheduled departure was 17:45, used on 56 of 344 flights, with 18:50 (48 flights) and 19:30 (35 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 17:4556 flights16.3%
Departs 18:5048 flights14.0%
Departs 19:3035 flights10.2%

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 17:45 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and DL 1677 runs 5 points worse at 62.9%. 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 1677 next to BOS to AUS

Every carrier on BOS to AUS combined arrived on time 72.2% of the time across 1,634 flights, so DL 1677 is 9 points behind it. Delta flew 988 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 19 points.

DL 1677 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 1677thin sample	344	62.9%	113 min	4.07%	D−
All Delta Air Lines on BOS–AUS	988	74.9%	93 min	2.63%	C
All carriers on BOS–AUS	1,634	72.2%	77 min	1.96%	C
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 1677 quarter by quarter

DL 1677 did not run the same all year. Its best quarter was Jan–Mar 2026 at 78.5% on time and its weakest Jul–Sep 2025 at 50.0%, a swing of 29 points on roughly 86 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 202583 flights50.0%
Oct–Dec 202586 flights55.4%
Jan–Mar 202687 flights78.5%
Apr–Jun 202688 flights67.8%

Scale runs 40% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, DL 1677 did best on Saturday at 72.2% on time and worst on Friday at 55.1%. Each day rests on about 49 flights, so a gap of 17 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 1677 runs late

One category carries most of the weight here. Carrier accounts for 49% of the 14,000 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
49%
Late-arriving aircraft
30%
National Airspace System
20%
Extreme weather
1%

The largest share of delay minutes, 49%, 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 6,735 of the 14,000 delay minutes reported here. The split is drawn from 13,772 delay minutes reported on DL 1677.

Cancellations run at 4.07%, against 1.81% nationally. That is about one flight in 25 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. 17.3% 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.

At 1,698 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 344 flights under DL 1677 in the data flew BOS to AUS. 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. 344 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 1677

For a booking, the cancellation rate is the figure to plan around on DL 1677: 4.07% of its 344 scheduled flights did not operate. A late arrival costs close to two hours, but a cancellation costs the day, so leave a later option open.

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