Detroit (DTW) to Seattle (SEA): On-Time Performance
Data through July 2026
The calendar drives reliability on DTW–SEA. November 2024 flights landed on schedule 92% of the time, but December 2025 dropped to 38% — a gap of 54 points. Across the full period the route averages 79% on-time against a national 78%. Morning departures also hold up better than evening ones (84% vs 73%), which matters most in the rough months.
- On-time
- 79%
- arrived <15 min late
- Avg delay
- 13 min
- completed flights
- Cancelled
- 0.8%
- Flights/day
- 5.7
- last 12 months
- Duration
- 5h 2m
- scheduled
- Distance
- 1,927 mi
Best airline from DTW to SEA
2 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Delta Air Linesmost reliable | 79% | 13 min | 0.9% | 3,240 |
| Alaska Airlines | 78% | 12 min | 0.5% | 1,111 |
Monthly on-time trend
Best time to fly from DTW to SEA
Aim for departures around 6 a.m. (88% on-time); avoid 9 a.m. departures (68%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 79% | 13 min |
| Tuesdaybest | 83% | 11 min |
| Wednesday | 80% | 11 min |
| Thursday | 78% | 13 min |
| Friday | 75% | 15 min |
| Saturday | 81% | 11 min |
| Sunday | 76% | 15 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft28%
- Airline operations46%
- National airspace system23%
- Weather3%
Frequently asked questions
- How often are flights from DTW to SEA delayed?
- 21% of DTW–SEA flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 13 minutes.
- Which airline is most reliable from DTW to SEA?
- Delta Air Lines has the best on-time record on this route at 79%, based on 3,240 flights. 2 airlines flew DTW–SEA frequently enough to compare in this period.
- What is the best time of day to fly from DTW to SEA?
- Departures around 6 a.m. have the best record (88% on-time), while departures around 9 a.m. have the worst (68%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from DTW to SEA?
- The scheduled DTW–SEA flight time averages 5h 2m over 1,927 miles. Actual arrival times vary — flights on this route land 15+ minutes late 21% of the time.
- How often are DTW to SEA flights cancelled?
- 0.8% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from DTW to SEA?
- December 2025 was the roughest month in this dataset, with only 38% of arrivals on time. The best was November 2024 at 92%. If your dates are flexible, that 54-point gap is worth planning around.
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Based on 4,351 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.