Carrier route record
ASSEA→MCI
Alaska Airlines · Seattle to Kansas City
- Flights
- 745
- Period
- September 2025 to August 2026
- Share of route
- 66%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on SEA to MCI earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.3%. When something does go wrong the average delay runs about 45 minutes. That rests on 745 flights, with a median arrival 8 minutes early.
Set against the rest of the country, Alaska's SEA to MCI record is 7 points better than the US average of 77.3%. That gap is worth roughly 70 fewer late arrivals for every thousand flights.
Key figures
On time
84.3%
Arrivals under 15 minutes late, of 738 completed flights
Avg delay
45 min
Across delayed arrivals only, not all flights
Cancelled
0.40%
National rate is 1.89%
Whole route
81.2%
Every carrier on SEA to MCI, 1,126 flights
These figures cover 745 flights between September 2025 and August 2026. The median arrival is 8 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.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
Alaska against every carrier on SEA to MCI
Alaska flew 745 of the 1,126 flights on SEA to MCI, most of the route. Its 84.3% on time is 3 points better than the route as a whole, which runs 81.2%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Alaska at 84.3% to Southwest at 29.4%. 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Alaska Airlines (this page) | 745 | 84.3% | 45 min | 0.40% | B+ |
| Delta Air Linesthin sample | 364 | 77.4% | 77 min | 1.65% | B |
| Southwest Airlinesthin sample | 17 | 29.4% | 76 min | 0.00% | F+ |
Flight by flight
Alaska flight numbers on SEA to MCI
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 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 16 points, against half a point between the best and worst carrier.
- 5am–8am70 flights94.3%
- 8am–11am271 flights88.8%
- 11am–2pm125 flights78.4%
- 2pm–5pm19 flights—
- 5pm–8pm259 flights79.1%
- 8pm–5am1 flights—
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 78.4% on time against 94.3% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8am–11am window is the busiest, with 271 flights scheduled in it.
Across the year
Alaska on SEA to MCI through the year
December is the weak month at 75.5% on time, against 96.6% in April. 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. July was the busiest month here, with 92 flights.
Across the week, Saturday is the strongest day at 91.4% on time and Monday the weakest at 79.1%, a spread of 12 points.
Arrival by arrival
How late Alaska on SEA to MCI runs when it is late
Alaska on SEA to MCI often beats the schedule: 253 of 738 completed flights, 34%, arrived 15 minutes or more early. The 116 late arrivals split 52 under half an hour, 41 between 30 and 60 minutes, and 23 an hour or more.
- 15+ min early253 flights34.3%
- Within 15 min369 flights50.0%
- 15–29 min late52 flights7.0%
- 30–59 min late41 flights5.6%
- 1–2 hours late17 flights2.3%
- 2+ hours late6 flights0.8%
Scale runs 0% to 100%.
Share of 738 completed flights by arrival against schedule.
39 of 132 late departures made up the time and arrived on time, 30% of them. 23 flights left on time and still arrived late.
The worst days
Worst days for Alaska on SEA to MCI
The latest arrival of the period was on 4 September 2025, 4 hours 1 minute behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 4 September 2025 | 4 hours 1 minute | Carrier |
| 26 September 2025 | 3 hours 27 minutes | Carrier |
| 11 August 2026 | 3 hours 3 minutes | Late-arriving aircraft |
| 5 November 2025 | 2 hours 26 minutes | Carrier |
| 13 May 2026 | 2 hours 26 minutes | Carrier |
Delay causes
Why Alaska runs late on this route
Carrier accounts for 47% of the 5,177 delay minutes carriers reported here, and the remaining four split what is left.
- 47%Carrier
- 33%Late-arriving aircraft
- 18%National Airspace System
- 2%Extreme weather
The largest share of delay minutes, 47%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,445 of the 5,177 delay minutes reported here. The split is drawn from 5,177 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 94.3% on time here.
Cancellations are rare at 0.40%, 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
Badly late arrivals are rare here: only 3.1% land an hour or more behind schedule, against 8.3% 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 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.
The return leg runs 84.7% on time across 745 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
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 84.3% 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 MCI77.4%
- Alaska Airlines network-wide record
- Seattle-Tacoma International (SEA) delay statistics
- Kansas City International (MCI) 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.