Flight number record

DL 1252

Delta Air Lines · Salt Lake City to San Diego

Route: SLC → SAN
Departs: 17:10
Flights: 255
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1252, check with Delta Air Lines.

DL 1252 lands a B+, 5 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by roughly 55 minutes on average. That is a workable record, not a spotless one. That rests on 255 flights, with a median arrival 5 minutes early.

Set against the rest of the country, DL 1252's record is 5 points better than the US average of 77.6%. That gap is worth roughly 54 fewer late arrivals for every thousand flights.

On time

83.0%

Arrivals under 15 minutes late, of 253 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

1 hour+ late

4.0%

National rate is 8.1%

These figures cover 255 flights between July 2025 and June 2026. The median arrival is 5 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 1252 flies

DL 1252 flies SLC to SAN without a single fixed slot. Its most common scheduled departure was 17:10, used on 72 of 255 flights, with 17:45 (67 flights) and 17:50 (49 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 17:1072 flights28.2%
Departs 17:4567 flights26.3%
Departs 17:5049 flights19.2%

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 17:10 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and DL 1252 runs 15 points better at 83.0%. 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 1252 next to SLC to SAN

Every carrier on SLC to SAN combined arrived on time 83.2% of the time across 2,958 flights, so DL 1252 is about level with it. Delta flew 1,731 flights on the same city pair under all its flight numbers, including this one, and those ran 83.8% on time. Across its whole network Delta Air Lines managed 81.6%, close to this flight's figure.

DL 1252 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 1252thin sample	255	83.0%	53 min	0.00%	B+
All Delta Air Lines on SLC–SAN	1,731	83.8%	55 min	0.81%	B+
All carriers on SLC–SAN	2,958	83.2%	54 min	0.85%	B+
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 1252 quarter by quarter

DL 1252 did not run the same all year. Its best quarter was Jan–Mar 2026 at 93.2% on time and its weakest Jul–Sep 2025 at 79.7%, a swing of 14 points on roughly 64 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 202560 flights79.7%
Oct–Dec 202577 flights81.6%
Jan–Mar 202644 flights93.2%
Apr–Jun 202674 flights81.1%

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, DL 1252 did best on Tuesday at 93.0% on time and worst on Thursday at 73.2%. Each day rests on about 36 flights, so a gap of 20 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 1252 runs late

One category carries most of the weight here. Carrier accounts for 65% of the 2,289 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
65%
Late-arriving aircraft
18%
National Airspace System
17%

The largest share of delay minutes, 65%, 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 1,489 of the 2,289 delay minutes reported here. The split is drawn from 2,289 delay minutes reported on DL 1252.

Cancellations are rare at 0.00%, below the national 1.81% and low enough to earn the plus on the grade. Almost no flights are 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 4.0% 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.

The same number turns up on two other city pairs in the data, including SAN to SLC (71) and MSP to ATL (3), but none flew often enough under DL 1252 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SLC to SAN only.

One caution: this is a thin sample. 255 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 1252

For a booking, read DL 1252 as 83.0% on time with 0.00% cancelled over 255 flights. Those are rates from the past twelve months, not a forecast for any particular 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