Carrier route record
ASSEA→MCI
Alaska Airlines · Seattle to Kansas City
- Flights
- 745
- Period
- July 2025 to June 2026
- Share of route
- 66%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on SEA to MCI lands a B+, 2 points 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 roughly 50 minutes on average. That is a workable record, not a spotless one. That rests on 745 flights, with a median arrival 5 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate Alaska on SEA to MCI from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
79.3%
Arrivals under 15 minutes late, of 738 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
0.54%
National rate is 1.81%
Whole route
77.7%
Every carrier on SEA to MCI, 1,131 flights
These figures cover 745 flights between July 2025 and June 2026. The median arrival is 5 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 SEA to MCI
Alaska flew 745 of the 1,131 flights on SEA to MCI, most of the route. Its 79.3% on time is 2 points better than the route as a whole, which runs 77.7%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Alaska at 79.3% to Southwest at 45.5%. 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Alaska Airlines (this page) | 745 | 79.3% | 48 min | 0.54% | B+ |
| Delta Air Linesthin sample | 364 | 76.6% | 68 min | 1.65% | B |
| Southwest Airlinesthin sample | 22 | 45.5% | 55 min | 0.00% | F+ |
Flight by flight
Alaska flight numbers on SEA to MCI
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 17 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–8am21 flights—
- 8am–11am313 flights86.8%
- 11am–2pm132 flights72.7%
- 2pm–5pm24 flights—
- 5pm–8pm254 flights70.3%
- 8pm–5am1 flights—
Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 86.8% of the time, against 70.3% for the evening window. That is 17 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 313 flights scheduled in it.
Across the year
Alaska on SEA to MCI through the year
July is the worst month at 50.0% on time, 47 points below April, the best at 96.6%. 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. June was the busiest month here, with 89 flights.
Across the week, Wednesday is the strongest day at 84.2% on time and Friday the weakest at 74.4%. 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. Carrier accounts for 47% of the 7,367 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.
- 47%Carrier
- 31%Late-arriving aircraft
- 19%National Airspace System
- 3%Extreme weather
The largest share of delay minutes, 47%, 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 3,459 of the 7,367 delay minutes reported here. The split is drawn from 7,367 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 86.8% on time here.
Cancellations are rare at 0.54%, 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
5.1% 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 roughly 50 minutes, which a normal layover absorbs.
The 1,490 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 83.0% on time across 745 flights, 4 points above 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 4 points of difference.
One caution: this is a thin sample. 745 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 Alaska on SEA to MCI
Put together: treat all of this as provisional. 745 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 79.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 738 completed flights over 12 months sit behind that.
Related
Where to go next
- SEA to MCI, every carrier
- Alaska on MCI to SEA, the return leg
- Delta Air Lines on SEA to MCI76.6%
- Alaska Airlines network-wide record
- Seattle-Tacoma International (SEA) delay statistics
- Kansas City International (MCI) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
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.