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Route · BLI → SEA · 2020–2025 BTS data

Bellingham to Seattle

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), BLI to SEA (Bellingham to Seattle) ranks #2092 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

84.5%
On-time
+5.5 pts
vs US avg
65 min
Delay when late
5,955
Flights
#2092 of 4927
Corpus placement

Cancelled

1.3%

Best Month

Nov 2025 92%

Worst Month

Sep 2024 54%

Distance

93 mi

Carriers

2

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 124 31 2 1 OO
Nov 2025 96 8 10 0 OO
Oct 2025 117 21 2 0 OO
Sep 2025 120 20 0 0 OO
Aug 2025 124 17 1 0 OO
Jul 2025 124 19 1 0 OO
Jun 2025 119 33 0 0 OO
May 2025 119 18 0 0 OO
Apr 2025 95 18 0 0 OO
Mar 2025 104 21 1 0 OO
Feb 2025 104 34 2 0 OO
Jan 2025 113 27 5 1 OO
Dec 2024 82 13 4 0 OO
Nov 2024 83 14 1 0 OO
Oct 2024 88 18 0 0 OO
Sep 2024 85 39 1 0 OO
Aug 2024 88 28 1 0 OO
Jul 2024 88 15 0 0 OO
Jun 2024 85 21 0 0 OO
May 2024 83 10 0 0 OO
Apr 2024 83 16 0 0 OO
Mar 2024 80 17 0 0 OO
Feb 2024 58 9 0 0 OO
Jan 2024 62 24 0 0 OO

BLI–SEA seasonal on-time pattern

Best: May (90.9%) · weakest: December (77.7%)

75%80%85%90%95% JanFebMarAprMayJunJulAugSepOctNovDec 77.7%

Strongest calendar month

May

90.9% on-time · ~101 flights/mo

Busiest calendar month

July

~115 flights/mo avg

Weakest calendar month

December

77.7% on-time · ~96 flights/mo

Cancellation Rate

1.3%

31 of 2,324 flights

Diversion Rate

0.1%

2 of 2,324 flights

Explore origin & destination

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

BLI - Bellingham

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

BLI 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 BLI and SEA side by side on delays, cancellations, and reliability.

Compare BLI vs SEA

Origin-hub reliability standing

Mid-pack among BLI departures

From BLI, this corridor sits with 2 other 75–85% on-time routes out of 3 tracked departures, not the hub's reliability leaders (1 at ≥85%) and not the softest ( 0 below 75%). Destination: Seattle · fleet on-time rank #1390 of 4927.

What the Data Says About BLI to SEA

Bureau of Transportation Statistics records show Bellingham to Seattle (BLI to SEA) running a 84.5% on-time rate over 5,955 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 64.5 minutes. The 93-mile corridor is served by 2 carriers, and over the last 24 months 1.3% of 2,324 flights were cancelled, 0.1% diverted.

The monthly split is wide on this route: Nov 2025 posted the strongest performance at 92% on-time, while Sep 2024 came in at just 54% - a 38-point swing worth factoring into travel timing.

On the multi-year calendar, BLI–SEA peaks in May at 90.9% on-time while July carries the heaviest traffic (~115 flights per month) ; the softest month is December at 77.7%, a 13.2-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does BLI to SEA rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, BLI to SEA ranks #2092 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 BLI to SEA? ▼
Flights from Bellingham to Seattle have a 84.5% on-time rate based on 5,955 flights. The average delay is 64.5 minutes. The best recent month was Nov 2025 with 92% on-time.
What is the cancellation rate for BLI to SEA? ▼
Over the last 24 months, 1.3% of flights on this route were cancelled (31 of 2,324 flights) and 0.1% were diverted.
How far is the flight from BLI to SEA? ▼
The flight distance from Bellingham (BLI) to Seattle (SEA) is approximately 93 miles. This route is served by 2 carriers.
When is the best time to fly from BLI to SEA? ▼
The best recent month for on-time performance was Nov 2025 (92% on-time). The worst was Sep 2024 (54% on-time). Consider booking during months with historically better performance.

Airports on this route

BLI Airport

Bellingham
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 BLI–SEA data

BLI–SEA runs 5.5 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare BLI and SEA airport profiles: delay causes and top routes differ even on the same corridor. BLI airport
  • If your dates flex, May (90.9% on-time) beats December (77.7%) on this corridor. Seasonal chart
  • 4 other routes post a similar 84.5% 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.