Carrier route record
DLSLC→LAX
Delta Air Lines · Salt Lake City to Los Angeles
- Flights
- 2,454
- Period
- July 2025 to June 2026
- Share of route
- 59%
- Carriers
- 6
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on SLC to LAX earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 50 minutes. That rests on 2,454 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 691 at 89.6% on time.
SkyWest Airlines is the most reliable of the three carriers covered here at 89.6% on time across 691 flights.
Key figures
On time
85.4%
Arrivals under 15 minutes late, of 2,444 completed flights
Avg delay
51 min
Across delayed arrivals only, not all flights
Cancelled
0.41%
National rate is 1.81%
Whole route
86.2%
Every carrier on SLC to LAX, 4,146 flights
These figures cover 2,454 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.
Carrier by carrier
Delta against every carrier on SLC to LAX
Delta flew 2,454 of the 4,146 flights on SLC to LAX, most of the route. Its 85.4% on time is about level with the route as a whole at 86.2%. Ranked by on-time rate it is number five of six carriers on the route, where the range runs from United at 91.9% to Southwest at 80.4%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 89.6% of the time; Southwest Airlines manages 80.4%. Sample sizes sit next to every figure, because a two-point gap across 374 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlinesthin sample | 148 | 91.9% | 34 min | 0.00% | A+ |
| Spirit Airlinesthin sample | 23 | 90.9% | 29 min | 4.35% | A− |
| SkyWest Airlines | 691 | 89.6% | 78 min | 0.00% | A+ |
| Frontier Airlines | 456 | 88.4% | 74 min | 1.54% | A |
| Delta Air Lines (this page) | 2,454 | 85.4% | 51 min | 0.41% | A+ |
| Southwest Airlines | 374 | 80.4% | 46 min | 0.27% | B+ |
SkyWest leads Southwest by 9 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
Delta flight numbers on SLC to LAX
Departure window
When Delta runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 13 points, against 9 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am337 flights92.8%
- 8am–11am385 flights91.4%
- 11am–2pm365 flights87.6%
- 2pm–5pm370 flights79.5%
- 5pm–8pm365 flights84.0%
- 8pm–5am632 flights80.8%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 92.8% of the time, against 79.5% for the afternoon window. That is 13 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 632 flights scheduled in it.
Across the year
Delta on SLC to LAX through the year
July is the worst month at 81.6% on time, 9 points below August, the best at 90.8%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. March was the busiest month here, with 213 flights.
Across the week, Wednesday is the strongest day at 88.4% on time and Sunday the weakest at 81.6%. 7 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Delta runs late on this route
One category carries most of the weight here. Carrier accounts for 51% of the 18,000 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.
- 51%Carrier
- 31%Late-arriving aircraft
- 14%National Airspace System
- 5%Extreme weather
The largest share of delay minutes, 51%, 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 9,217 of the 18,000 delay minutes reported here. The split is drawn from 18,130 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 92.8% on time here.
Cancellations are rare at 0.41%, 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 stage length
What a delay here costs
Badly late arrivals are rare here: only 3.4% 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 590 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 return leg is a different operation and performs like one: it runs 88.5% on time across 2,451 flights, 3 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 3 points of difference.
The sample behind these figures is 2,454 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking Delta on SLC to LAX
Put together: take the 5am–8am departure, avoid July if the dates are flexible, and if two carriers are within a few dollars of each other, SkyWest is the one with the record behind it. None of that guarantees an on-time arrival; it moves the odds by 13 points, which is the most any booking decision can do. 2,444 completed flights over 12 months sit behind that.
Related
Where to go next
- SLC to LAX, every carrier
- Delta on LAX to SLC, the return leg
- United Airlines on SLC to LAX91.9%
- SkyWest Airlines on SLC to LAX89.6%
- Frontier Airlines on SLC to LAX88.4%
- Southwest Airlines on SLC to LAX80.4%
- Delta Air Lines network-wide record
- Salt Lake City International (SLC) delay statistics
- Los Angeles International (LAX) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
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.