Carrier route record
WNSMF→LAX
Southwest Airlines · Sacramento to Los Angeles
- Flights
- 1,660
- Period
- September 2025 to August 2026
- Share of route
- 29%
- Carriers
- 5
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on SMF to LAX lands a B+, level with the national rate of 77.3%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by roughly 50 minutes on average. That rests on 1,660 flights, with a median arrival 3 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Southwest on SMF to LAX from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
77.1%
Arrivals under 15 minutes late, of 1,654 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
0.30%
National rate is 1.89%
Whole route
85.6%
Every carrier on SMF to LAX, 5,717 flights
These figures cover 1,660 flights between September 2025 and August 2026. The median arrival is 3 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.
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Carrier by carrier
Southwest against every carrier on SMF to LAX
Southwest flew 1,660 of the 5,717 flights on SMF to LAX, about 29% of it. Its 77.1% on time is 9 points worse than the route as a whole, which runs 85.6%. Ranked by on-time rate it is number four of five carriers on the route, where the range runs from Delta at 92.7% to Frontier at 72.5%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Linesthin sample | 55 | 92.7% | 31 min | 0.00% | A+ |
| United Airlinesthin sample | 202 | 91.6% | 72 min | 0.00% | A+ |
| SkyWest Airlines | 3,558 | 89.9% | 87 min | 0.39% | A+ |
| Southwest Airlines (this page) | 1,660 | 77.1% | 48 min | 0.30% | B+ |
| Frontier Airlinesthin sample | 242 | 72.5% | 62 min | 2.48% | C |
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 32 points, against half a point between the best and worst carrier.
- 5am–8am334 flights94.0%
- 8am–11am305 flights88.2%
- 11am–2pm169 flights84.5%
- 2pm–5pm257 flights69.3%
- 5pm–8pm376 flights62.3%
- 8pm–5am219 flights64.8%
Scale runs 55% to 100%.
The 5pm–8pm window is where this operation falls apart: 62.3% on time, against 94.0% 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 5pm–8pm window is the busiest, with 376 flights scheduled in it.
Across the year
Southwest on SMF to LAX through the year
June is the worst month at 69.7% on time, 16 points below January, the best at 85.4%. 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. August was the busiest month here, with 162 flights.
Across the week, Wednesday is the strongest day at 84.9% on time and Sunday the weakest at 68.9%, a spread of 16 points.
Arrival by arrival
How late Southwest on SMF to LAX runs when it is late
The 379 late arrivals split 157 under half an hour, 133 between 30 and 60 minutes, and 89 an hour or more.
- 15+ min early280 flights16.9%
- Within 15 min995 flights60.2%
- 15–29 min late157 flights9.5%
- 30–59 min late133 flights8.0%
- 1–2 hours late67 flights4.1%
- 2+ hours late22 flights1.3%
Scale runs 0% to 100%.
Share of 1,654 completed flights by arrival against schedule.
121 of 470 late departures made up the time and arrived on time, 26% of them. Only 30 left on time and still arrived late.
The worst days
Worst days for Southwest on SMF to LAX
The latest arrival of the period was on 8 June 2026, 4 hours 43 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 8 June 2026 | 4 hours 43 minutes | Late-arriving aircraft |
| 17 April 2026 | 4 hours 3 minutes | Late-arriving aircraft |
| 6 November 2025 | 3 hours 56 minutes | Late-arriving aircraft |
| 2 July 2026 | 3 hours 47 minutes | Late-arriving aircraft |
| 18 September 2025 | 3 hours 31 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 67% of the 18,000 delay minutes carriers reported here, and the remaining four split what is left.
- 67%Late-arriving aircraft
- 23%Carrier
- 9%National Airspace System
- 1%Extreme weather
- 0%Security
67% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 18,000 reported delay minutes here, that single category outweighs weather by 67 to one. The split is drawn from 18,232 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 94.0% on time here.
Cancellations are rare at 0.30%, below the national 1.89% 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
5.4% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 50 minutes, which a normal layover absorbs.
At 373 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 runs 79.0% on time across 1,650 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 1,660 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 Southwest on SMF to LAX
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 85.4% on time and June 69.7%, a swing of 16 points. If the dates move at all, move them out of June before you think about anything else. 1,654 completed flights over 12 months sit behind that.
Related
Where to go next
- SMF to LAX, every carrier
- Southwest on LAX to SMF, the return leg
- United Airlines on SMF to LAX91.6%
- SkyWest Airlines on SMF to LAX89.9%
- Frontier Airlines on SMF to LAX72.5%
- Southwest Airlines network-wide record
- Sacramento International (SMF) delay statistics
- Los Angeles International (LAX) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.