Flight number record

DL 1177

Delta Air Lines · San Diego to Salt Lake City

Route: SAN → SLC
Departs: 09:45
Flights: 364
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1177, check with Delta Air Lines.

DL 1177 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 14 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 364 flights, with a median arrival 9 minutes early.

Set against the rest of the country, DL 1177's record is 14 points better than the US average of 77.6%. That gap is worth roughly 141 fewer late arrivals for every thousand flights.

On time

91.7%

Arrivals under 15 minutes late, of 360 completed flights

Avg delay

92 min

Across delayed arrivals only, not all flights

Cancelled

0.82%

National rate is 1.81%

1 hour+ late

4.2%

National rate is 8.1%

These figures cover 364 flights between July 2025 and June 2026. The median arrival is 9 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 1177 flies

DL 1177 flies SAN to SLC without a single fixed slot. Its most common scheduled departure was 09:45, used on 125 of 364 flights, with 09:50 (91 flights) and 09:47 (51 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 09:45125 flights34.3%
Departs 09:5091 flights25.0%
Departs 09:4751 flights14.0%

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 09:45 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and DL 1177 runs 8 points better at 91.7%. 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 1177 next to SAN to SLC

Every carrier on SAN to SLC combined arrived on time 84.4% of the time across 2,961 flights, so DL 1177 is 7 points ahead of it. Delta flew 1,732 flights on the same city pair under all its flight numbers, including this one, and those ran 88.7% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 10 points.

DL 1177 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 1177thin sample	364	91.7%	92 min	0.82%	A+
All Delta Air Lines on SAN–SLC	1,732	88.7%	77 min	0.81%	A+
All carriers on SAN–SLC	2,961	84.4%	65 min	0.71%	B+
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 1177 quarter by quarter

Quarter by quarter DL 1177 held fairly steady: 85.9% in Jul–Sep 2025, 93.3% in Oct–Dec 2025, 95.5% in Jan–Mar 2026 and 92.2% in Apr–Jun 2026. A spread of 10 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights85.9%
Oct–Dec 202591 flights93.3%
Jan–Mar 202690 flights95.5%
Apr–Jun 202691 flights92.2%

Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, DL 1177 ranged from 86.5% on Thursday to 98.1% on Monday. With about 52 flights behind each day, a spread of 12 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why DL 1177 runs late

One category carries most of the weight here. Late-arriving aircraft accounts for 47% of the 2,756 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.

Late-arriving aircraft
47%
Carrier
44%
National Airspace System
9%

47% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 2,756 reported delay minutes here, that single category outweighs weather by 47 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 2,756 delay minutes reported on DL 1177.

Cancellations are rare at 0.82%, 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

Badly late arrivals are rare here: only 4.2% 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.

The 626 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.

DL 1177 is not only a SAN to SLC flight. It also flew SLC to SAN (364 flights, 92.2% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.

One caution: this is a thin sample. 364 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.

Other routes flown as DL 1177
Also flown as	Flights	On time	Avg delay	Cancelled	Grade
SLC to SANthin sample	364	92.2%	57 min	0.82%	A+

What to do with this

Booking DL 1177

For a booking, DL 1177 has one of the better records a US domestic flight can show: 91.7% on time and 0.82% cancelled. That is a base rate, not a promise about any single 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