Kansas City (MCI) to Seattle (SEA): On-Time Performance
Data through May 2026
Kansas City (MCI) to Seattle (SEA) effectively runs on two schedules. In October 2024, 97% of arrivals were on time; in December 2025 that fell to 66% — a 30-point seasonal swing. Across the full period the route averages 83% on-time against a national 78%. Morning departures also hold up better than evening ones (88% vs 60%), which matters most in the rough months.
- On-time
- 83%
- arrived <15 min late
- Avg delay
- 12 min
- completed flights
- Cancelled
- 1.3%
- Flights/day
- 3.1
- last 12 months
- Duration
- 4h 2m
- scheduled
- Distance
- 1,490 mi
Best airline from MCI to SEA
3 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Delta Air Linesmost reliable | 87% | 12 min | 1.8% | 728 |
| Alaska Airlines | 82% | 11 min | 1.1% | 1,496 |
| Southwest Airlines | 58% | 25 min | 0.0% | 60 |
Monthly on-time trend
Best time to fly from MCI to SEA
Aim for departures around 6 a.m. (90% on-time); avoid 7 p.m. departures (60%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 87% | 9 min |
| Tuesdaybest | 87% | 10 min |
| Wednesday | 84% | 12 min |
| Thursday | 83% | 11 min |
| Friday | 80% | 18 min |
| Saturday | 81% | 11 min |
| Sunday | 81% | 11 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft29%
- Airline operations45%
- National airspace system21%
- Weather5%
Frequently asked questions
- How often are flights from MCI to SEA delayed?
- 17% of MCI–SEA flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 12 minutes.
- Which airline is most reliable from MCI to SEA?
- Delta Air Lines has the best on-time record on this route at 87%, based on 728 flights. 3 airlines flew MCI–SEA frequently enough to compare in this period.
- What is the best time of day to fly from MCI to SEA?
- Departures around 6 a.m. have the best record (90% on-time), while departures around 7 p.m. have the worst (60%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from MCI to SEA?
- The scheduled MCI–SEA flight time averages 4h 2m over 1,490 miles. Actual arrival times vary — flights on this route land 15+ minutes late 17% of the time.
- How often are MCI to SEA flights cancelled?
- 1.3% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from MCI to SEA?
- December 2025 was the roughest month in this dataset, with only 66% of arrivals on time. The best was October 2024 at 97%. If your dates are flexible, that 30-point gap is worth planning around.
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Based on 2,284 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.