Carrier route record

WNTUS→LAX

Southwest Airlines · Tucson to Los Angeles

Flights: 466
Period: July 2025 to June 2026
Share of route: 18%
Carriers: 2

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

Southwest on TUS to LAX lands a B+, 6 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 about 45 minutes on average. That is a workable record, not a spotless one. That rests on 466 flights, with a median arrival 7 minutes early.

Set against the rest of the country, Southwest's TUS to LAX record is 6 points better than the US average of 77.6%. That gap is worth roughly 56 fewer late arrivals for every thousand flights.

On time

83.2%

Arrivals under 15 minutes late, of 464 completed flights

Avg delay

45 min

Across delayed arrivals only, not all flights

Cancelled

0.43%

National rate is 1.81%

Whole route

85.9%

Every carrier on TUS to LAX, 2,581 flights

These figures cover 466 flights between July 2025 and June 2026. The median arrival is 7 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 TUS to LAX

Southwest flew 466 of the 2,581 flights on TUS to LAX, about 18% of it. Its 83.2% on time is 3 points worse than the route as a whole, which runs 85.9%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 86.5% to Southwest at 83.2%.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on TUS to LAX
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	2,115	86.5%	85 min	0.43%	A+
Southwest Airlines (this page)	466	83.2%	45 min	0.43%	B+

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 36 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am62 flights91.8%
8am–11am118 flights88.1%
11am–2pm91 flights85.6%
2pm–5pm91 flights84.6%
5pm–8pm50 flights84.0%
8pm–5am54 flights55.6%

Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 55.6% on time, against 91.8% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8am–11am window is the busiest, with 118 flights scheduled in it.

Across the year

Southwest on TUS to LAX through the year

Darker means more delays. Figures are on-time percentages.September best, May worst

September is the best month on the calendar at 93.3% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. May was the busiest month here, with 48 flights.

Across the week, Saturday is the strongest day at 92.3% on time and Sunday the weakest at 76.0%. 16 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 65% of the 3,541 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
65%
Carrier
20%
National Airspace System
15%
Extreme weather
1%

65% 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 3,541 reported delay minutes here, that single category outweighs weather by 65 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 3,541 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 91.8% on time here.

Cancellations are rare at 0.43%, 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.

At 451 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 68.2% on time across 466 flights, 15 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 15 points of difference.

One caution: this is a thin sample. 466 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 TUS to LAX

Put together: treat all of this as provisional. 466 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 83.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 464 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