Airport · SEA · Seattle, Washington

Seattle, WA

Seattle, WA posts below-median on-time performance among the 382 tracked U.S. airports, as one of the busiest U.S. airports. According to the U.S. DOT Bureau of Transportation Statistics, drawn from 1,871,155 flights (2020–2025); its biggest delay driver is carrier.

Compiled by PlainFlights Editorial, Flight Performance Editorial Team

Data updated 2026-06-13

83.1%
On-time: Top 54%
on-time, US airports: 63 min
Delay when late: 0.73%
Cancelled

Key Performance Metrics

Total Flights

1,871,155

Best Month

Oct 93.3%

Worst Month

Dec 89%

Delayed

315,819

Cancelled

13,720

60-65%

1
65-70%

4
70-75%

9
75-80%

48
80-85%

192
85-90%

116
90-95%

12

What this shows SEA is marked in the 80-85% band.

Delay Cause Breakdown

Top delay cause: Carrier. Total delay minutes: 8,961,455.

Late Aircraft 28.6% (2,565,832 min)

Carrier 44.3% (3,971,615 min)

NAS (National Aviation System) 21.0% (1,877,657 min)

Weather 5.8% (522,011 min)

Security 0.3% (24,340 min)

Seasonal Performance Patterns

Monthly averages across all years of data. Best month: October (93.3% on-time). Most delays: December (89% on-time).

Month	Avg Flights	Avg Delayed	Avg Cancelled	On-Time %
December	24,692	5,379	391	89%
November	24,824	3,615	104	92.8%
October	27,026	3,610	76	93.3%
September	28,013	4,033	53	92.6%
August	30,041	5,587	93	90.5%
July	29,615	5,808	136	90%
June	27,396	5,802	124	89.3%
May	25,309	4,003	100	92.1%
April	23,559	3,490	315	92.5%
March	25,643	3,706	369	92.6%
February	22,165	3,512	187	92.4%
January	23,578	4,092	340	91.3%

Year-Over-Year Performance

Annual flight volume and on-time trends at SEA.

Year	Flights	Delayed	Cancelled	On-Time %
2025	329,669	34,644	1,348	89.5%
2024	327,431	33,301	1,813	89.8%
2023	327,598	28,505	986	91.3%
2022	348,016	30,176	3,473	91.3%
2021	336,018	23,903	2,399	92.9%
2020	202,423	8,843	3,701	95.6%

Cancellation & Diversion Analysis

Flight disruption statistics for Seattle, WA.

Cancellation Rate

0.73%

13,720 of 1,871,155 flights

Diversion Rate

0.11%

2,147 of 1,871,155 flights

Delay Rate

16.9%

315,819 of 1,871,155 flights

Monthly Performance

Recent 24 months of flight data.

Period	Flights	Dep Delayed	Arr Delayed	Cancelled	Diverted
Dec 2025	26,039	3,524	3,859	133	33
Nov 2025	25,226	2,050	2,222	213	93
Oct 2025	27,716	2,427	2,506	161	24
Sep 2025	29,115	2,406	2,281	42	33
Aug 2025	31,946	3,935	3,837	106	51
Jul 2025	33,153	4,559	4,176	228	86
Jun 2025	31,388	4,345	4,340	98	51
May 2025	29,255	2,851	3,071	53	26
Apr 2025	25,439	2,140	2,071	23	26
Mar 2025	25,149	2,198	2,178	45	20
Feb 2025	21,468	2,211	2,198	137	19
Jan 2025	23,775	1,998	2,015	109	54
Dec 2024	25,185	2,557	2,250	63	37
Nov 2024	24,904	1,671	1,646	46	9
Oct 2024	27,519	1,950	1,797	53	23
Sep 2024	29,615	2,749	2,687	48	20
Aug 2024	31,967	3,882	3,766	128	44
Jul 2024	32,398	3,974	4,001	272	36
Jun 2024	30,369	4,058	4,056	70	33
May 2024	28,671	3,286	3,211	70	30
Apr 2024	25,842	2,432	2,147	25	13
Mar 2024	25,254	2,427	2,078	40	30
Feb 2024	22,199	1,506	1,360	33	20
Jan 2024	23,508	2,809	2,427	965	97

Top Routes from SEA

Busiest routes to and from Seattle, WA.

Route	Flights	On-Time	Distance
SEA (Seattle) → LAX (Los Angeles)	41,859	84%	954 mi
LAX (Los Angeles) → SEA (Seattle)	41,819	86.2%	954 mi
SEA (Seattle) → ANC (Anchorage)	41,143	77.5%	1,448 mi
ANC (Anchorage) → SEA (Seattle)	41,064	85.8%	1,448 mi
PHX (Phoenix) → SEA (Seattle)	38,561	84.3%	1,107 mi
SEA (Seattle) → PHX (Phoenix)	38,549	82.3%	1,107 mi
SFO (San Francisco) → SEA (Seattle)	37,671	82.1%	679 mi
SEA (Seattle) → SFO (San Francisco)	37,651	79.1%	679 mi
DEN (Denver) → SEA (Seattle)	37,116	77.8%	1,024 mi
SEA (Seattle) → DEN (Denver)	37,112	81.1%	1,024 mi
LAS (Las Vegas) → SEA (Seattle)	36,175	81.5%	867 mi
SEA (Seattle) → LAS (Las Vegas)	36,154	80.3%	867 mi
PDX (Portland) → SEA (Seattle)	36,148	87.7%	129 mi
SEA (Seattle) → PDX (Portland)	35,578	83.7%	129 mi
GEG (Spokane) → SEA (Seattle)	31,745	86.5%	224 mi
SEA (Seattle) → GEG (Spokane)	31,686	83.3%	224 mi
ORD (Chicago) → SEA (Seattle)	27,916	79.9%	1,721 mi
SEA (Seattle) → ORD (Chicago)	27,905	82%	1,721 mi
SEA (Seattle) → SJC (San Jose)	26,361	85%	696 mi
SJC (San Jose) → SEA (Seattle)	26,343	86.4%	696 mi

Airports With a Similar On-Time Rate

Other U.S. airports nationwide whose on-time rate is closest to Seattle, WA's 83.1%.

Madison, WI

83.1% on-time 127,239 flights

Rapid City, SD

83.1% on-time 58,593 flights

Shreveport, LA

83.1% on-time 55,112 flights

Fairbanks, AK

83.1% on-time 44,233 flights

Marquette, MI

83.1% on-time 12,906 flights

Joplin, MO

83.1% on-time 8,632 flights

Other Airports in Washington

Compare performance with other Washington airports.

GEG 84.4%

Spokane, WA

Spokane · 205,595 flights

PSC 86.9%

Pasco/Kennewick/Richland, WA

Pasco/Kennewick/Richland · 63,750 flights

BLI 85.8%

Bellingham, WA

Bellingham · 29,229 flights

PAE 84.3%

Everett, WA

Everett · 19,411 flights

PUW 86.6%

Pullman, WA

Pullman · 4,696 flights

ALW 88.8%

Walla Walla, WA

Walla Walla · 4,519 flights

EAT 87.3%

Wenatchee, WA

Wenatchee · 2,841 flights

YKM 88%

Yakima, WA

Yakima · 2,733 flights

Keep exploring

More flight data around Seattle, WA.

Washington flight data

Statewide on-time and delay aggregates, plus every reporting airport in Washington.

View WA data →

Airport rankings

See where SEA sits among U.S. airports on on-time rate and average delay.

Best on-time airports →

Compare airports

Put SEA head-to-head with another airport on delays and reliability.

Open comparison tool →

What the Data Says About SEA

Seattle, WA in Seattle, Washington handled 1,871,155 flights in the Bureau of Transportation Statistics dataset between 2020 and 2025, posting a 83.1% on-time departure rate. Of those flights, 315,819 experienced delays, 13,720 were cancelled, and 2,147 were diverted. The cancellation rate works out to 0.73%, the diversion rate to 0.11%, and the average delay when departures run late is 63.4 minutes. These figures are the baseline for comparing SEA against other airports in the same state and nationally.

Breaking down what drives delays at SEA, Carrier leads the pack. Carrier accounts for 44.3% of total delay minutes, followed by Late Aircraft at 28.6% and NAS (National Aviation System) at 21.0%. Weather contributes 5.8% of delay minutes at this airport, while security holds the smallest share at 0.3%. Travelers often overestimate the weather share; the BTS categorization shows late-arriving aircraft and carrier operations as the larger contributors.

Seasonally, October runs the cleanest at SEA with a 93.3% on-time rate, while December is the roughest at 89% - a 4-point swing between best and worst month. Volume peaks in August, when average flights hit 30,041. The busiest route connecting SEA is to LAX (Los Angeles), with 41,859 flights at a 84% on-time rate. Combine these numbers - 83.1% on-time, 63.4-minute average delay, 0.73% cancellation rate, and you have a concrete picture of departure reliability at Seattle, WA.

Frequently Asked Questions

What is the on-time performance rate at Seattle, WA (SEA)? ▼

Seattle, WA has an overall on-time departure rate of 83.1%. Out of 1,871,155 total flights tracked, 315,819 experienced delays and 13,720 were cancelled.

What is the most common cause of delays at SEA? ▼

The top delay cause at Seattle, WA is Carrier. Carrier accounts for 44.3% of all delay minutes.

What is the average delay time at SEA? ▼

The average delay at Seattle, WA is 63.4 minutes. This includes delays from carrier issues, weather, National Aviation System constraints, security, and late-arriving aircraft.

What is the best month to fly from SEA? ▼

Based on historical data, October has the best on-time performance at SEA with 93.3% of flights departing on time.

What is the worst month for delays at SEA? ▼

December tends to have the most delays at SEA, with an on-time rate of only 89%.

How many routes operate from SEA? ▼

Seattle, WA serves at least 20 routes. The busiest route is SEA to LAX (Seattle - Los Angeles) with 41,859 flights.

What is the cancellation rate at SEA? ▼

Seattle, WA has a cancellation rate of 0.73%, based on 13,720 cancelled flights out of 1,871,155 total flights tracked.

Flight Guides

Data-driven guides to help you understand airport and flight performance.

Best & Worst Airlines for On-Time Performance

Which carriers consistently outperform peers

Why Flights Get Cancelled

Cancellation causes broken down by data

How to Choose Reliable Flight Routes

Use delay data to pick flights that arrive on time

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Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data (2020–2025). Statistics reflect cumulative performance across all available reporting periods. On-time rates exclude cancelled and diverted flights.

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

Using SEA's data

An airport-level on-time rate is a starting point, not a guarantee for your specific flight.

Check the busiest route from SEA before you book a connection. See top routes
Travel in October rather than December if your dates are flexible. Seasonal patterns
Scores vary by airline and route within the same airport; check the specific carrier you're flying. Browse airlines

On-time rate reflects the BTS historical average across all reporting carriers at this airport, not any single flight or airline.

All airports → | Rankings →

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 Editorial

Source: U.S. Bureau of Transportation Statistics (BTS) Airline on-time performance and operational reliability · 2025 Accessed 2026-07-23

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. Airport figures are computed directly from BTS On-Time Performance data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.