Flight number record

DL 671

Delta Air Lines · Salt Lake City to New York

Route: SLC → JFK
Departs: 14:30
Flights: 363
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 671, check with Delta Air Lines.

DL 671 lands a B, 2 points worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 363 flights, with a median arrival 15 minutes early.

On time

76.1%

Arrivals under 15 minutes late, of 355 completed flights

Avg delay

65 min

Across delayed arrivals only, not all flights

Cancelled

1.65%

National rate is 1.81%

1 hour+ late

10.1%

National rate is 8.1%

These figures cover 363 flights between July 2025 and June 2026. Beyond the headline rate, 10.1% 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 671 flies

DL 671 flies SLC to JFK without a single fixed slot. Its most common scheduled departure was 14:30, used on 51 of 363 flights, with 14:29 (41 flights) and 13:37 (38 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 14:3051 flights14.0%
Departs 14:2941 flights11.3%
Departs 13:3738 flights10.5%

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 14:30 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and DL 671 runs 4 points better at 76.1%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

DL 671 next to SLC to JFK

Every carrier on SLC to JFK combined arrived on time 82.0% of the time across 1,931 flights, so DL 671 is 6 points behind it. Delta flew 1,538 flights on the same city pair under all its flight numbers, including this one, and those ran 83.5% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 6 points.

DL 671 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 671thin sample	363	76.1%	65 min	1.65%	B
All Delta Air Lines on SLC–JFK	1,538	83.5%	68 min	1.63%	B
All carriers on SLC–JFK	1,931	82.0%	76 min	1.92%	B
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 671 quarter by quarter

DL 671 did not run the same all year. Its best quarter was Jan–Mar 2026 at 81.4% on time and its weakest Jul–Sep 2025 at 67.4%, a swing of 14 points on roughly 91 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 202592 flights67.4%
Oct–Dec 202590 flights75.0%
Jan–Mar 202690 flights81.4%
Apr–Jun 202691 flights80.9%

Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, DL 671 did best on Friday at 90.0% on time and worst on Sunday at 64.0%. Each day rests on about 52 flights, so a gap of 26 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 671 runs late

One category carries most of the weight here. National Airspace System accounts for 45% of the 5,545 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
45%
Carrier
28%
Late-arriving aircraft
19%
Extreme weather
7%

45% 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 2,517 minutes out of 5,545, against a national NAS share of 21%. The split is drawn from 5,545 delay minutes reported on DL 671.

Cancellations sit at 1.65% against a national 1.81%, which is ordinary. Diversions add another 0.55%.

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. 10.1% 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 1,990 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 363 flights under DL 671 in the data flew SLC to JFK. 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. 363 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 671

For a booking, DL 671 is one of the weaker ways to fly SLC to JFK: 6 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.

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