Carrier route record

WNLGB→SLC

Southwest Airlines · Long Beach to Salt Lake City

Flights: 463
Period: July 2025 to June 2026
Share of route: 30%
Carriers: 3

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.

Southwest on LGB to SLC 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 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 50 minutes. That rests on 463 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 622 at 93.1% on time.

Set against the rest of the country, Southwest's LGB to SLC record is 9 points better than the US average of 77.6%. That gap is worth roughly 87 fewer late arrivals for every thousand flights.

On time

86.3%

Arrivals under 15 minutes late, of 460 completed flights

Avg delay

50 min

Across delayed arrivals only, not all flights

Cancelled

0.22%

National rate is 1.81%

Whole route

89.1%

Every carrier on LGB to SLC, 1,552 flights

These figures cover 463 flights between July 2025 and June 2026. The median arrival is 8 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

Southwest against every carrier on LGB to SLC

Southwest flew 463 of the 1,552 flights on LGB to SLC, about 30% of it. Its 86.3% on time is 3 points worse than the route as a whole, which runs 89.1%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from SkyWest at 93.1% to Southwest at 86.3%.

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 93.1% of the time; Delta Air Lines manages 86.6%. Sample sizes sit next to every figure, because a two-point gap across 467 flights means less than a ten-point one.

On-time performance by carrier on LGB to SLC
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	622	93.1%	87 min	0.00%	A+
Delta Air Lines	467	86.6%	90 min	0.86%	A+
Southwest Airlines (this page)	463	86.3%	50 min	0.22%	A+

SkyWest leads Delta by 7 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Departure window

When Southwest runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 29 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am3 flights—
8am–11am176 flights96.0%
11am–2pm104 flights87.3%
2pm–5pm117 flights84.6%
5pm–8pm51 flights66.7%
8pm–5am12 flights—

Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 96.0% of the time, against 66.7% for the evening window. That is 29 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 176 flights scheduled in it.

Across the year

Southwest on LGB to SLC through the year

Darker means more delays. Figures are on-time percentages.November best, June worst

June is the worst month at 67.4% on time, 33 points below November, the best at 100.0%. 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. February was the busiest month here, with 46 flights.

Across the week, Wednesday is the strongest day at 92.2% on time and Sunday the weakest at 80.3%. 12 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 79% of the 3,137 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
79%
Carrier
18%
National Airspace System
3%
Extreme weather
0%

79% 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 3,137 reported delay minutes here, that single category outweighs weather by 79 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 3,137 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 96.0% on time here.

Cancellations are rare at 0.22%, 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 3.9% 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 588 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 77.3% on time across 463 flights, 9 points below 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 9 points of difference.

One caution: this is a thin sample. 463 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 Southwest on LGB to SLC

Put together: treat all of this as provisional. 463 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 86.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 460 completed flights over 12 months sit behind that.

Where to go next

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