SEA to MIA flight delays & on-time performance
Nonstop flights from Seattle–Tacoma International Airport to Miami International Airport · 2,724 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at SEA or MIA right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Seattle (SEA) to Miami (MIA) arrived on time 78% of the time in Aug 2025 – Jul 2026, in line with the national average.
- 0.9% were cancelled, and 6% arrived an hour or more late.
- Alaska Airlines was the most punctual airline here (80% on time); American Airlines was the least (77%).
- Departures scheduled around 7am did best (88% on time); around 1pm did worst (73%).
- Wednesday was the most reliable day to fly (83% on time) and Friday the least (74%).
- The largest source of delay minutes was airline (crew, maintenance, cleaning, fueling) (45%).
Which airline is most on time from SEA to MIA?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| Alaska Airlines | 80% | 0.5% | 9 min | 3.1% | 391 |
| Delta Air Lines | 79% | 1.4% | 14 min | 5.6% | 365 |
| American Airlines | 77% | 0.9% | 18 min | 7.6% | 454 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 7am88%184 flights
- 8am77%544 flights
- 12pm85%47 flights
- 1pm73%42 flights
- 8pm76%164 flights
- 9pm71%28 flights
- 10pm73%162 flights
- 11pm91%36 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday76%1.7% cancelled
- Tuesday81%0.6% cancelled
- Wednesday83%0.6% cancelled
- Thursday81%0.6% cancelled
- Friday74%1.1% cancelled
- Saturday76%0.0% cancelled
- Sunday79%1.7% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Airline (crew, maintenance, cleaning, fueling)45%
- Air traffic control & airport congestion29%
- Late-arriving aircraft25%
- Extreme weather2%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Airline (crew, maintenance, cleaning, fueling)64%
- Extreme weather27%
- Air traffic control & airport congestion9%
- Security0%
SEA to MIA: common questions
- How often are SEA to MIA flights on time?
- 78% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Seattle to Miami cancelled?
- 0.9% of scheduled flights were cancelled (11 of 1,210).
- How long are typical delays?
- Across all flights the average arrival delay was 14 min (early arrivals count as zero). Flights that were late arrived 58 min behind schedule on average, and 5.5% of flights were an hour or more late.
- How long is taxi time at SEA?
- Flights on this route spent 23 min taxiing from the gate to takeoff on average.
Related routes
Return trip: MIA to SEA — 67% on time
More flights from Seattle
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: SEA → MIA, nonstop flights by US airlines that report to the DOT. How we calculate this.