Route profile
MCI→SEA
Flight reliability, delays and best times to fly from Kansas City to Seattle, 1,489 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 87% of comparable major US routes (4,598 compared)
Calculated from 3,584 flights. How this is calculated
MCI → SEA arrives on time 84.5% of the time; the return trip, SEA → MCI, arrives on time 78.5% of the time, a 6.0-point gap between the two directions of the same city pair.
MCI → SEA spends 30.2 minutes on the ground on a 1,489-mile trip: 18.3 minutes from pushback to wheels-up at MCI and 11.8 minutes from touchdown to gate at SEA.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
This route has stayed remarkably steady year over year, a smaller swing than 100% of 5,368 comparable routes.
85.0% on time over the most recent 12 months (2025-08 to 2026-07), against 85.0% in the 12 months before (2024-08 to 2025-07), virtually unchanged.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 5,368 in the comparison.
When it goes wrong
July 2023 – July 2026
26 min late
against a median of 8 min early
Percentiles over 3,584 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SEA after arriving from MCI.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 32% | Likely to miss |
| 45 min | 15% | Some risk |
| 60 min | 8.5% | Some risk |
| 90 min | 3.8% | Low risk |
| 120 min | 2.4% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 1.06% of the time and diverts 0.31% of the time, which a late arrival never shows up in.
Chance of missing is the share of 3,535 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 26 minutes late (90th-percentile gate arrival delay), over 3,584 operations.
Any other layover length: connection checker.
Best time to fly
MCI → SEA flights departing 5–9 AM arrived on time 89.9% of the time, against 64.7% for 6–9 PM departures, a gap of 25.2 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 90.6% on time from 991 flights
- 7 AM: 89.4% on time from 1,067 flights
- 8 AM to 12 PM: too few flights to score
- 1 PM: 77.6% on time from 126 flights
- 2 PM: 86.2% on time from 632 flights
- 3 PM: 77.5% on time from 308 flights
- 4 PM to 6 PM: too few flights to score
- 7 PM: 63.8% on time from 381 flights
- 8 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why MCI → SEA runs late
July 2023 – July 2026
crew, maintenance, boarding and fueling, all within the carrier’s control
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for MCI → SEA. Only delays of 15 minutes or more are attributed.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Alaska Airlines | 2,384 | 83.2% | 0.96% | -6 min | 3.4% |
| Delta Air Lines | 1,122 | 89.0% | 1.34% | -12 min | 4.4% |
Alaska Airlines flew 68.0% of the 3,506 flights listed.
Delta Air Lines arrived on time 5.8 percentage points more often than Alaska Airlines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Friday the least, a gap of 4.9 percentage points.
By month
- Jan: 78.7%
- Feb: 85.8%
- Mar: 89.4%
- Apr: 88.5%
- May: 86.3%
- Jun: 79.5%
- Jul: 81.2%
- Aug: 82.4%
- Sep: 85.8%
- Oct: 89.7%
- Nov: 86.9%
- Dec: 84.6%
January is historically the weakest month and October the strongest, a spread of 11.0 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 78.9% from 124 flights
- August 2023: 83.9% from 124 flights
- September 2023: too few flights to score (116)
- October 2023: too few flights to score (93)
- November 2023: too few flights to score (87)
- December 2023: too few flights to score (86)
- January 2024: too few flights to score (68)
- February 2024: too few flights to score (66)
- March 2024: too few flights to score (87)
- April 2024: too few flights to score (90)
- May 2024: too few flights to score (109)
- June 2024: 74.6% from 128 flights
- July 2024: 78.9% from 131 flights
- August 2024: 82.5% from 127 flights
- September 2024: too few flights to score (116)
- October 2024: too few flights to score (87)
- November 2024: too few flights to score (79)
- December 2024: too few flights to score (85)
- January 2025: too few flights to score (67)
- February 2025: too few flights to score (63)
- March 2025: too few flights to score (79)
- April 2025: too few flights to score (85)
- May 2025: too few flights to score (105)
- June 2025: 73.8% from 124 flights
- July 2025: 76.4% from 127 flights
- August 2025: 80.8% from 121 flights
- September 2025: too few flights to score (111)
- October 2025: too few flights to score (88)
- November 2025: too few flights to score (79)
- December 2025: too few flights to score (85)
- January 2026: too few flights to score (68)
- February 2026: too few flights to score (56)
- March 2026: too few flights to score (74)
- April 2026: too few flights to score (90)
- May 2026: too few flights to score (109)
- June 2026: 90.2% from 123 flights
- July 2026: 90.6% from 127 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 85.0% against 85.0% in the 12 months before — broadly unchanged.
Data and methodology
Calculated by FlyerIntel from 3,584 MCI → SEA flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed