Carrier route record

WNSMF→LAS

Southwest Airlines · Sacramento to Las Vegas

Flights: 3,432
Period: July 2025 to June 2026
Share of route: 81%
Carriers: 4

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

Southwest on SMF to LAS lands a B+, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 55 minutes on average. That is a workable record, not a spotless one. That rests on 3,432 flights, with a median arrival 4 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Southwest on SMF to LAS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

78.7%

Arrivals under 15 minutes late, of 3,418 completed flights

Avg delay

54 min

Across delayed arrivals only, not all flights

Cancelled

0.35%

National rate is 1.81%

Whole route

80.1%

Every carrier on SMF to LAS, 4,238 flights

These figures cover 3,432 flights between July 2025 and June 2026. The median arrival is 4 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 SMF to LAS

Southwest flew 3,432 of the 4,238 flights on SMF to LAS, most of the route. Its 78.7% on time is about level with the route as a whole at 80.1%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from SkyWest at 90.7% to Frontier at 76.4%. Two 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.

On-time performance by carrier on SMF to LAS
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	405	90.7%	90 min	1.48%	A
Spirit Airlinesthin sample	190	86.0%	69 min	2.11%	A
Southwest Airlines (this page)	3,432	78.7%	54 min	0.35%	B+
Frontier Airlinesthin sample	211	76.4%	77 min	1.42%	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 27 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–8am597 flights94.5%
8am–11am644 flights91.0%
11am–2pm558 flights75.0%
2pm–5pm689 flights70.3%
5pm–8pm511 flights67.7%
8pm–5am433 flights69.8%

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

Book the early departure. Flights leaving between 5am–8am arrive on time 94.5% of the time, against 67.7% for the evening window. That is 27 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 689 flights scheduled in it.

Across the year

Southwest on SMF to LAS through the year

Darker means more delays. Figures are on-time percentages.February best, October worst

Delays peak in October, when the on-time rate falls to 72.2%. February is the strongest month at 85.8%. Moving a flexible trip across that boundary buys 14 points. May was the busiest month here, with 303 flights.

Across the week, Saturday is the strongest day at 85.8% on time and Friday the weakest at 72.7%. 13 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 54% of the 40,000 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.

Late-arriving aircraft
54%
Carrier
24%
National Airspace System
21%
Extreme weather
1%
Security
0%

54% 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 40,000 reported delay minutes here, that single category outweighs weather by 39 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 39,508 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 94.5% on time here.

Cancellations are rare at 0.35%, 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

6.0% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 55 minutes, which a normal layover absorbs.

At 397 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 77.0% on time across 3,432 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 3,432 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 LAS

Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 85.8% on time and October 72.2%, a swing of 14 points. If the dates move at all, move them out of October before you think about anything else. 3,418 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