Carrier route record

OOSEA→LAX

SkyWest Airlines · Seattle to Los Angeles

Flights: 1,241
Period: July 2025 to June 2026
Share of route: 17%
Carriers: 6

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

SkyWest on SEA 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 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs close to two hours. That rests on 1,241 flights. The strongest carrier on the route with a full sample, United Airlines, flew 393 at 90.3% on time.

United Airlines is the most reliable of the three carriers covered here at 90.3% on time across 393 flights.

On time

86.3%

Arrivals under 15 minutes late, of 1,231 completed flights

Avg delay

109 min

Across delayed arrivals only, not all flights

Cancelled

0.64%

National rate is 1.81%

Whole route

83.4%

Every carrier on SEA to LAX, 7,428 flights

These figures cover 1,241 flights between July 2025 and June 2026. The median arrival is 11 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

SkyWest against every carrier on SEA to LAX

SkyWest flew 1,241 of the 7,428 flights on SEA to LAX, about 17% of it. Its 86.3% on time is 3 points better than the route as a whole, which runs 83.4%. Ranked by on-time rate it is number three of six carriers on the route, where the range runs from American at 90.9% to Frontier at 78.9%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. United Airlines arrives on time 90.3% of the time; Alaska Airlines manages 81.0%. Sample sizes sit next to every figure, because a two-point gap across 3,282 flights means less than a ten-point one.

On-time performance by carrier on SEA to LAX
Airline	Flights	On time	Avg delay	Cancelled	Grade
American Airlinesthin sample	11	90.9%	149 min	0.00%	A+
United Airlines	393	90.3%	98 min	0.00%	A+
SkyWest Airlines (this page)	1,241	86.3%	109 min	0.64%	A+
Delta Air Lines	2,225	84.5%	59 min	0.67%	B+
Alaska Airlines	3,282	81.0%	43 min	1.07%	B
Frontier Airlinesthin sample	276	78.9%	60 min	3.62%	B−

United leads Alaska by 9 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Departure window

When SkyWest runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 17 points, against 9 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am328 flights82.8%
8am–11am243 flights91.4%
11am–2pm154 flights97.4%
2pm–5pm222 flights85.1%
5pm–8pm278 flights80.8%
8pm–5am16 flights—

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

The best window here is not the first bank but the 11am–2pm slot at 97.4% on time, ahead of 5pm–8pm at 80.8%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 5am–8am window is the busiest, with 328 flights scheduled in it.

Across the year

SkyWest on SEA to LAX through the year

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

July is the worst month at 80.6% on time, 14 points below June, the best at 94.1%. 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 169 flights.

Across the week, Tuesday is the strongest day at 91.9% on time and Monday the weakest at 83.1%. 9 points is a smaller lever than departure hour, but it is free.

Delay causes

Why SkyWest runs late on this route

One category carries most of the weight here. Carrier accounts for 68% 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.

Carrier
68%
Late-arriving aircraft
19%
Extreme weather
6%
National Airspace System
6%

The largest share of delay minutes, 68%, 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 13,000 of the 18,000 delay minutes reported here. The split is drawn from 18,427 reported delay minutes.

Cancellations are rare at 0.64%, 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

6.2% 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 close to two hours, which a normal layover absorbs.

The 954 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 runs 84.6% on time across 1,239 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 1,241 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 SkyWest on SEA to LAX

Put together: the calendar is the biggest lever here, not the carrier or the hour. June runs 94.1% on time and July 80.6%, a swing of 14 points. If the dates move at all, move them out of July before you think about anything else. 1,231 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