PlainFlights

Route · SEA → MIA · 2020–2025 BTS data

Seattle to Miami

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SEA to MIA (Seattle to Miami) ranks #3115 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

78.6%
On-time
-0.4 pts
vs US avg
72 min
Delay when late
3,504
Flights
#3115 of 4927
Corpus placement

Cancelled

1.2%

Best Month

Oct 2025 90%

Worst Month

Aug 2025 65%

Distance

2,724 mi

Carriers

6

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 120 27 1 0 DL,AS,AA
Nov 2025 97 18 1 1 AA,AS,DL
Oct 2025 93 9 1 0 AA,AS,DL
Sep 2025 90 17 0 1 DL,AA,AS
Aug 2025 93 33 1 0 AA,AS,DL
Jul 2025 93 28 2 1 AA,AS,DL
Jun 2025 90 24 0 0 AA,AS,DL
May 2025 92 13 0 0 AA,AS,DL
Apr 2025 90 14 0 0 AA,AS,DL
Mar 2025 93 14 0 0 AA,AS,DL
Feb 2025 84 15 0 0 AA,AS,DL
Jan 2025 102 22 0 0 AA,AS,DL
Dec 2024 103 25 0 0 AA,AS,DL
Nov 2024 69 14 0 1 AS,AA
Oct 2024 62 6 3 1 AS,AA
Sep 2024 60 10 1 0 AA,AS
Aug 2024 62 20 2 0 AA,AS
Jul 2024 62 17 0 0 AA,AS
Jun 2024 60 8 2 0 AA,AS
May 2024 62 11 0 0 AA,AS
Apr 2024 60 6 0 0 AA,AS
Mar 2024 62 14 0 0 AA,AS
Feb 2024 58 10 0 0 AA,AS
Jan 2024 69 24 9 0 AA,AS

SEA–MIA seasonal on-time pattern

Best: October (89.2%) · weakest: August (68.1%)

65%70%75%80%85%90%95% JanFebMarAprMayJunJulAugSepOctNovDec 71.7%

Strongest calendar month

October

89.2% on-time · ~70 flights/mo

Busiest calendar month

December

~80 flights/mo avg

Weakest calendar month

August

68.1% on-time · ~62 flights/mo

Cancellation Rate

1.2%

23 of 1,926 flights

Diversion Rate

0.3%

5 of 1,926 flights

Explore origin & destination

On-time and delay data for the airports this route connects.

SEA - Seattle

Full on-time, delay-cause, and seasonal performance for Seattle, WA.

SEA on-time profile

MIA - Miami

Full on-time, delay-cause, and seasonal performance for Miami, FL.

MIA on-time profile

Compare the two airports

See SEA and MIA side by side on delays, cancellations, and reliability.

Compare SEA vs MIA

Origin-hub reliability standing

Mid-pack among SEA departures

From SEA, this corridor sits with 63 other 75–85% on-time routes out of 89 tracked departures, not the hub's reliability leaders (25 at ≥85%) and not the softest ( 1 below 75%). Destination: Miami · fleet on-time rank #3656 of 4927.

What the Data Says About SEA to MIA

3,504 tracked flights put the SEA to MIA pairing (Seattle to Miami) at a 78.6% on-time rate, squarely in line with the wider network. Delays that do occur run 71.8 minutes on average. Across the 2,724-mile route and its 6 carriers, the trailing 24 months show 1.2% cancelled and 0.3% diverted (1,926 flights sampled).

The monthly split is wide on this route: Oct 2025 posted the strongest performance at 90% on-time, while Aug 2025 came in at just 65% - a 26-point swing worth factoring into travel timing.

On the multi-year calendar, SEA–MIA peaks in October at 89.2% on-time while December carries the heaviest traffic (~80 flights per month) ; the softest month is August at 68.1%, a 21.1-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does SEA to MIA rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, SEA to MIA ranks #3115 of 4927 tracked domestic routes by total flights (most flights = #1). That ordinal matches our busiest-routes listing (total_flights DESC). See /methodology#corpus-placement for the exact sort basis.
How often are flights delayed from SEA to MIA? ▼
Flights from Seattle to Miami have a 78.6% on-time rate based on 3,504 flights. The average delay is 71.8 minutes. The best recent month was Oct 2025 with 90% on-time.
What is the cancellation rate for SEA to MIA? ▼
Over the last 24 months, 1.2% of flights on this route were cancelled (23 of 1,926 flights) and 0.3% were diverted.
How far is the flight from SEA to MIA? ▼
The flight distance from Seattle (SEA) to Miami (MIA) is approximately 2,724 miles. This route is served by 6 carriers.
When is the best time to fly from SEA to MIA? ▼
The best recent month for on-time performance was Oct 2025 (90% on-time). The worst was Aug 2025 (65% on-time). Consider booking during months with historically better performance.

Airports on this route

SEA Airport

Seattle
MIA Airport

Miami
Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Read our methodology - how this data is sourced, computed, and verified.

Using SEA–MIA data

SEA–MIA is mid-pack at 78.6% on-time; month and carrier mix move more than the corridor headline.

  • Compare SEA and MIA airport profiles: delay causes and top routes differ even on the same corridor. SEA airport
  • If your dates flex, October (89.2% on-time) beats August (68.1%) on this corridor. Seasonal chart
  • 4 other routes post a similar 78.6% on-time rate; compare before you commit to this pairing. Similar routes

On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.