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Route · MIA → SEA · 2020–2025 BTS data

Miami to Seattle

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), MIA to SEA (Miami to Seattle) ranks #3098 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

70.7%
On-time
-8.3 pts
vs US avg
77 min
Delay when late
3,534
Flights
#3098 of 4927
Corpus placement

Cancelled

1.6%

Best Month

Oct 2024 85%

Worst Month

Aug 2025 54%

Distance

2,724 mi

Carriers

6

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 121 39 1 2 DL,AS,AA
Nov 2025 96 29 2 0 AA,AS,DL
Oct 2025 93 20 1 0 AA,AS,DL
Sep 2025 90 32 0 0 DL,AA,AS
Aug 2025 93 43 1 1 AA,AS,DL
Jul 2025 93 32 2 0 AA,AS,DL
Jun 2025 90 27 0 0 AA,AS,DL
May 2025 93 30 0 1 AA,AS,DL
Apr 2025 90 21 0 0 DL,AA,AS
Mar 2025 93 35 0 1 AA,AS,DL
Feb 2025 84 21 0 1 AA,AS,DL
Jan 2025 103 26 0 1 AA,AS,DL
Dec 2024 103 34 1 0 AA,AS,DL
Nov 2024 68 11 0 1 AS,AA
Oct 2024 62 9 4 0 AS,AA
Sep 2024 60 13 1 0 AA,AS
Aug 2024 62 17 3 0 AA,AS
Jul 2024 62 28 0 0 AA,AS
Jun 2024 60 25 2 0 AA,AS
May 2024 62 28 0 0 AA,AS
Apr 2024 60 15 0 0 AA,AS
Mar 2024 62 21 2 1 AA,AS
Feb 2024 58 15 0 0 AA,AS
Jan 2024 69 19 11 0 AA,AS

MIA–SEA seasonal on-time pattern

Best: October (80.3%) · weakest: July (64.5%)

60%65%70%75%80%85% JanFebMarAprMayJunJulAugSepOctNovDec 69.9%

Strongest calendar month

October

80.3% on-time · ~70 flights/mo

Busiest calendar month

December

~80 flights/mo avg

Weakest calendar month

July

64.5% on-time · ~62 flights/mo

Cancellation Rate

1.6%

31 of 1,927 flights

Diversion Rate

0.5%

9 of 1,927 flights

Explore origin & destination

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

MIA - Miami

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

MIA on-time profile

SEA - Seattle

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

SEA on-time profile

Compare the two airports

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

Compare MIA vs SEA

Origin-hub reliability standing

Softer reliability from MIA

Among 63 routes leaving MIA, only 25 (including this one) clear below 75% on-time, while 1 stay ≥85% and 37 sit mid-band. Travelers comparing MIA options should weigh this 70.7% print against those peers · fleet on-time rank #4823 of 4927.

What the Data Says About MIA to SEA

On-time performance on the MIA to SEA pairing (Miami to Seattle) trails a chunk of the network: 70.7% of 3,534 tracked flights arrived on schedule, with a 77.4-minute average delay on the ones that ran late. The route spans about 2,724 miles across 6 carriers. Cancellations over the trailing 24 months hit 1.6% (31 of 1,927 flights), with 0.5% diverted.

The monthly split is wide on this route: Oct 2024 posted the strongest performance at 85% on-time, while Aug 2025 came in at just 54% - a 32-point swing worth factoring into travel timing.

On the multi-year calendar, MIA–SEA peaks in October at 80.3% on-time while December carries the heaviest traffic (~80 flights per month) ; the softest month is July at 64.5%, a 15.8-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does MIA to SEA rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, MIA to SEA ranks #3098 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 MIA to SEA? ▼
Flights from Miami to Seattle have a 70.7% on-time rate based on 3,534 flights. The average delay is 77.4 minutes. The best recent month was Oct 2024 with 85% on-time.
What is the cancellation rate for MIA to SEA? ▼
Over the last 24 months, 1.6% of flights on this route were cancelled (31 of 1,927 flights) and 0.5% were diverted.
How far is the flight from MIA to SEA? ▼
The flight distance from Miami (MIA) to Seattle (SEA) is approximately 2,724 miles. This route is served by 6 carriers.
When is the best time to fly from MIA to SEA? ▼
The best recent month for on-time performance was Oct 2024 (85% on-time). The worst was Aug 2025 (54% on-time). Consider booking during months with historically better performance.

Airports on this route

MIA Airport

Miami
SEA Airport

Seattle
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 MIA–SEA data

MIA–SEA sits 8.3 pts below the national 79% average; check the seasonal chart and airport profiles before treating the headline as typical.

  • Compare MIA and SEA airport profiles: delay causes and top routes differ even on the same corridor. MIA airport
  • If your dates flex, October (80.3% on-time) beats July (64.5%) on this corridor. Seasonal chart
  • 4 other routes post a similar 70.7% 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.