Flight number record

DL 2817

Delta Air Lines · Salt Lake City to Seattle

Route: SLC → SEA
Departs: 15:25
Flights: 363
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 2817, check with Delta Air Lines.

DL 2817 sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 363 flights, with a median arrival 6 minutes early.

On time

75.1%

Arrivals under 15 minutes late, of 362 completed flights

Avg delay

51 min

Across delayed arrivals only, not all flights

Cancelled

0.28%

National rate is 1.81%

1 hour+ late

7.2%

National rate is 8.1%

These figures cover 363 flights between July 2025 and June 2026. The median arrival is 6 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 2817 flies

DL 2817 flies SLC to SEA without a single fixed slot. Its most common scheduled departure was 15:25, used on 97 of 363 flights, with 15:30 (55 flights) and 15:34 (45 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 15:2597 flights26.7%
Departs 15:3055 flights15.2%
Departs 15:3445 flights12.4%

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 15:25 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and DL 2817 runs 3 points better at 75.1%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

DL 2817 next to SLC to SEA

Every carrier on SLC to SEA combined arrived on time 80.2% of the time across 4,108 flights, so DL 2817 is 5 points behind it. Delta flew 2,222 flights on the same city pair under all its flight numbers, including this one, and those ran 83.3% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 7 points.

DL 2817 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 2817thin sample	363	75.1%	51 min	0.28%	B+
All Delta Air Lines on SLC–SEA	2,222	83.3%	54 min	0.54%	B+
All carriers on SLC–SEA	4,108	80.2%	53 min	0.97%	B+
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 2817 quarter by quarter

DL 2817 did not run the same all year. Its best quarter was Jan–Mar 2026 at 86.5% on time and its weakest Jul–Sep 2025 at 67.4%, a swing of 19 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 flights70.0%
Jan–Mar 202690 flights86.5%
Apr–Jun 202691 flights76.9%

Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, DL 2817 did best on Saturday at 82.7% on time and worst on Friday at 68.0%. Each day rests on about 52 flights, so a gap of 15 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 2817 runs late

One category carries most of the weight here. Carrier accounts for 46% of the 4,596 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
46%
Late-arriving aircraft
28%
National Airspace System
21%
Extreme weather
6%

The largest share of delay minutes, 46%, 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 2,106 of the 4,596 delay minutes reported here. The split is drawn from 4,596 delay minutes reported on DL 2817.

Cancellations are rare at 0.28%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and routes

What a delay on this flight costs

7.2% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 50 minutes, which a normal layover absorbs.

The 689 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.

Every one of the 363 flights under DL 2817 in the data flew SLC to SEA. 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 2817

For a booking, DL 2817 is one of the weaker ways to fly SLC to SEA: 5 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