Seattle/Tacoma International in August 2023

80.7%departed on time

BTS: A flight is counted as on time if it arrived less than 15 minutes after its scheduled time. Only carriers with at least 0.5 percent of domestic scheduled passenger revenue report.

In August 2023, reporting carriers scheduled 15,974 domestic departures from Seattle/Tacoma International (SEA). 80.7% left less than 15 minutes late and 78.1% reached their destination on time; 0.4% were cancelled.

Nationally that month, 76.7% of flights departed on time and 76.9% arrived on time, so SEA departures were 4.0 points above the national departure figure.

Flights arriving at SEA that month were on time 81.7% of the time (15,968 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, air carrier 42%, late-arriving aircraft 34% and national aviation system 20%.

On time 78.1%
Arrived 15+ minutes late 21.2%
Cancelled 0.4%
Diverted 0.3%

Every scheduled departure from SEA in August 2023, judged by arrival at the destination.

August 2023 against a year earlier, the airport's year and the nation

Measure	Aug 2023	Year earlier	SEA, 12 months to Jul 2026	All reported flights, Aug 2023
Departed on time	80.7%	—	78.2%	76.7%
Arrived on time	78.1%	—	78.6%	76.9%
Cancelled	0.4%	—	0.9%	1.5%
Average departure delay (late minutes only)	11.5 min	—	13.2 min	17.3 min
Scheduled departures a day	533	—	452	20,100
Scheduled departures	15,974	—	164,821	602,987

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
AS Alaska Airlines	7,772	49%	75.2%	6.3 min	0.1%
DL Delta Air Lines	3,204	20%	82.7%	3.0 min	0.9%
OO SkyWest Airlines	2,122	13%	86.2%	0.9 min	0.0%
UA United Airlines	974	6%	83.4%	0.8 min	0.3%
WN Southwest Airlines	876	5%	67.4%	13.2 min	0.8%
AA American Airlines	640	4%	77.0%	12.8 min	0.8%
B6 JetBlue Airways	182	1%	61.5%	19.1 min	2.2%
NK Spirit Airlines	75	0%	69.3%	24.7 min	1.3%
F9 Frontier Airlines	67	0%	71.6%	9.6 min	3.0%
HA Hawaiian Airlines	62	0%	74.2%	5.7 min	3.2%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
SEA–ANC	Seattle to Anchorage	850	79.2%	0.7 min	0.0%
SEA–LAX	Seattle to Los Angeles	734	78.7%	6.3 min	0.1%
SEA–DEN	Seattle to Denver	654	74.2%	7.8 min	0.5%
SEA–SFO	Seattle to San Francisco	616	78.6%	5.0 min	0.6%
SEA–PHX	Seattle to Phoenix	575	74.6%	6.4 min	0.5%
SEA–ORD	Seattle to Chicago	563	77.8%	6.3 min	0.4%
SEA–PDX	Seattle to Portland	557	78.1%	6.0 min	0.0%
SEA–LAS	Seattle to Las Vegas	546	71.2%	11.0 min	0.9%
SEA–SJC	Seattle to San Jose	439	81.8%	1.6 min	0.9%
SEA–SAN	Seattle to San Diego	429	74.1%	7.9 min	0.7%
SEA–DFW	Seattle to Dallas/Fort Worth	426	68.8%	13.8 min	0.0%
SEA–GEG	Seattle to Spokane	414	80.2%	6.6 min	0.7%

By scheduled departure hour

On-time share:under 62%6270768288% and over

Share of departures that left less than 15 minutes late, by scheduled hour (local time), August 2023.

Delay causes

BTS cause category	Share of delay minutes	National, Aug 2023	Minutes
Air carrier	42.4%	36.7%	71,534
Late-arriving aircraft	33.7%	42.2%	56,988
National Aviation System	20.0%	15.7%	33,842
Extreme weather	3.5%	5.1%	5,948
Security	0.3%	0.2%	589

168,901 delay minutes on 3,388 flights that arrived 15 or more minutes late and carried a cause report. Carriers assign the categories; see what each category means.

Questions and answers

How many flights left SEA on time in August 2023?

80.7% of 15,974 scheduled domestic departures left less than 15 minutes late, and 78.1% reached their destination on time. The national figures that month were 76.7% and 76.9%.

How does that compare with a year earlier?

August 2022 is outside the 36 months on file, or the airport had too few reported flights that month.

Provenance

Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for August 2023; public domain. Domestic scheduled flights by reporting carriers, totals and averages only. The site's data runs through July 2026. Full record for SEA · methodology · corrections.