Carrier route record
ASLAS→SEA
Alaska Airlines · Las Vegas to Seattle
- Flights
- 2,638
- Period
- July 2025 to June 2026
- Share of route
- 47%
- Carriers
- 6
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on LAS to SEA lands a B, 5 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 an hour on average. That is a workable record, not a spotless one. That rests on 2,638 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 1,738 at 87.6% on time.
Set against the rest of the country, Alaska's LAS to SEA record is 5 points better than the US average of 77.6%. That gap is worth roughly 52 fewer late arrivals for every thousand flights.
Key figures
On time
82.8%
Arrivals under 15 minutes late, of 2,604 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
1.25%
National rate is 1.81%
Whole route
82.3%
Every carrier on LAS to SEA, 5,649 flights
These figures cover 2,638 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
Alaska against every carrier on LAS to SEA
Alaska flew 2,638 of the 5,649 flights on LAS to SEA, about 47% of it. Its 82.8% on time is about level with the route as a whole at 82.3%. Ranked by on-time rate it is number four of six carriers on the route, where the range runs from Spirit at 88.4% to Southwest at 71.0%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 87.6% of the time; Southwest Airlines manages 71.0%. Sample sizes sit next to every figure, because a two-point gap across 977 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Spirit Airlinesthin sample | 43 | 88.4% | 47 min | 0.00% | A+ |
| Delta Air Lines | 1,738 | 87.6% | 87 min | 0.86% | A+ |
| SkyWest Airlinesthin sample | 7 | 85.7% | 59 min | 0.00% | A+ |
| Alaska Airlines (this page) | 2,638 | 82.8% | 64 min | 1.25% | B |
| Frontier Airlinesthin sample | 246 | 82.2% | 48 min | 0.81% | B+ |
| Southwest Airlines | 977 | 71.0% | 45 min | 0.31% | C+ |
The spread between Delta and Southwest is 17 points, wide enough that it should decide the booking. On a hundred trips that is 17 more arrivals inside the on-time window.
Flight by flight
Alaska flight numbers on LAS to SEA
Departure window
When Alaska runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 18 points, against 17 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am475 flights91.3%
- 8am–11am600 flights83.6%
- 11am–2pm550 flights85.5%
- 2pm–5pm360 flights76.2%
- 5pm–8pm496 flights78.6%
- 8pm–5am157 flights73.7%
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 91.3% of the time, against 73.7% for the overnight window. That is 18 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 600 flights scheduled in it.
Across the year
Alaska on LAS to SEA through the year
December is the weak month at 76.2% on time, against 94.5% in February. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. October was the busiest month here, with 240 flights.
Across the week, Tuesday is the strongest day at 87.3% on time and Friday the weakest at 77.5%. 10 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Alaska runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 29,000 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.
- 44%Late-arriving aircraft
- 33%Carrier
- 20%National Airspace System
- 3%Extreme weather
- 0%Security
44% 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 29,000 reported delay minutes here, that single category outweighs weather by 15 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 28,671 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 91.3% on time here.
Cancellations sit at 1.25% against a national 1.81%, which is ordinary. Diversions add another 0.04%.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 4.2% 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 867 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 78.0% on time across 2,638 flights, 5 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 5 points of difference.
The sample behind these figures is 2,638 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 Alaska on LAS to SEA
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 94.5% on time and December 76.2%, a swing of 18 points. If the dates move at all, move them out of December before you think about anything else. 2,604 completed flights over 12 months sit behind that.
Related
Where to go next
- LAS to SEA, every carrier
- Alaska on SEA to LAS, the return leg
- Delta Air Lines on LAS to SEA87.6%
- Frontier Airlines on LAS to SEA82.2%
- Southwest Airlines on LAS to SEA71.0%
- Alaska Airlines network-wide record
- Harry Reid International (LAS) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Why the first flight of the morning is statistically safest
- Same route, different airline: where the carrier you pick matters most
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.