Noise Event Reports & Graphs (Hours and Days)

Let’s see how busy it is…

This is one of several tools we offer to help make sense of publicly available data collected from the Port Of Seattle’s own Noise Monitoring system. Despite the long list of disclaimers below (which you should read both to understand the noise monitoring system and its significant limitations), we think you’ll find these reports very useful.

The three reports on this page are:

Busiest Hours of the Week: Displays 168 row of a virtual week (24 hours over seven days). If you ever wondered what time of day is most active over your neighborhood, this is for you.
Busiest Days of the Year: Displays 365 rows – one for each day of a virtual year. If you select Jan 1, 2024 to Dec 31, 2024 you’ll understand the busiest days of 2024. If you select Jan 1, 2021 to Dec 31, 2024 the report looks at three years and give you the busiest days of the years for all that
Busiest Hours of Each Day: Displays 105 rows – the 15 non-DNL hours of each day of the week ordered by most busy to least. If you ever wondered what is the busiest hour of every Wednesday, this is for you.

They can do a lot more than that by using the Filters explained below.

Report Type

Start Date

End Date

Show Report

Show Graph

Filters

Start by leaving all options checked. Use the filters to drill down into specific runways, monitors (neighborhood), airlines, and types of flights (passenger vs. cargo).

Busiest Times Of The Day (Outside of DNL)

January 1 - May 31, 2025 *This is an average altitude across the entire noise monitoring system.

DAY	HOUR	AVG FLIGHTS PER HOUR	NOISE DBA	*ALTITUDE
Sunday	10	65	83	1,904
Sunday	12	64	83	1,926
Sunday	8	62	83	2,002
Sunday	16	59	83	1,946
Sunday	18	58	83	1,889
Sunday	20	58	83	1,853
Sunday	14	57	83	1,831
Sunday	9	55	83	1,929
Sunday	21	51	82	1,784
Sunday	11	50	83	1,977
Sunday	13	50	83	1,936
Sunday	7	46	82	2,123
Sunday	17	46	83	1,920
Sunday	19	45	83	1,839
Sunday	15	42	83	2,074
Monday	12	65	83	1,917
Monday	10	63	83	1,864
Monday	20	62	82	1,831
Monday	16	61	83	1,916
Monday	18	60	83	1,860
Monday	8	60	83	1,965
Monday	9	57	83	1,909
Monday	14	54	83	1,886
Monday	21	51	83	1,786
Monday	11	51	83	1,927
Monday	19	48	83	1,856
Monday	17	45	83	1,836
Monday	7	45	83	2,095
Monday	13	44	83	1,954
Monday	15	44	83	2,038
Tuesday	10	65	83	1,863
Tuesday	12	62	83	1,882
Tuesday	18	58	83	1,832
Tuesday	8	58	83	2,037
Tuesday	16	56	83	1,861
Tuesday	14	55	83	1,807
Tuesday	9	54	82	1,950
Tuesday	20	52	82	1,810
Tuesday	11	48	83	1,922
Tuesday	7	46	82	2,138
Tuesday	21	46	83	1,741
Tuesday	17	45	83	1,851
Tuesday	15	42	83	1,998
Tuesday	19	41	82	1,826
Tuesday	13	40	83	1,883
Wednesday	12	70	83	1,971
Wednesday	10	70	82	1,920
Wednesday	18	66	82	1,939
Wednesday	8	64	82	2,016
Wednesday	9	61	83	1,979
Wednesday	20	57	82	1,835
Wednesday	16	56	83	1,888
Wednesday	11	56	82	1,915
Wednesday	14	56	82	1,901
Wednesday	21	51	82	1,711
Wednesday	7	48	82	2,124
Wednesday	13	45	82	2,001
Wednesday	15	45	82	1,997
Wednesday	17	45	82	1,889
Wednesday	19	45	82	1,812
Thursday	10	70	83	1,851
Thursday	12	70	83	1,893
Thursday	8	68	83	2,008
Thursday	18	67	83	1,933
Thursday	20	64	83	1,853
Thursday	9	62	83	1,899
Thursday	16	62	83	1,894
Thursday	14	58	83	1,841
Thursday	11	57	83	1,930
Thursday	21	56	83	1,798
Thursday	7	53	83	2,175
Thursday	19	48	83	1,932
Thursday	13	48	83	1,887
Thursday	17	47	83	1,771
Thursday	15	45	83	2,054
Friday	12	70	83	1,993
Friday	10	69	83	1,893
Friday	18	66	83	1,943
Friday	8	65	83	2,075
Friday	20	65	83	1,969
Friday	9	62	83	2,037
Friday	16	61	83	1,985
Friday	11	57	83	1,937
Friday	21	57	83	1,851
Friday	14	57	83	1,944
Friday	7	52	83	2,172
Friday	19	52	83	1,879
Friday	17	49	83	1,854
Friday	13	49	83	2,078
Friday	15	48	83	2,035
Saturday	10	67	83	1,903
Saturday	12	61	83	2,026
Saturday	8	61	83	1,995
Saturday	18	55	83	1,955
Saturday	14	54	83	1,895
Saturday	16	53	83	1,960
Saturday	11	50	83	1,972
Saturday	9	50	83	1,955
Saturday	7	49	83	2,049
Saturday	20	43	83	1,861
Saturday	15	42	83	1,897
Saturday	17	41	83	1,906
Saturday	13	41	83	1,985
Saturday	21	40	83	1,749
Saturday	19	36	83	1,840

All the disclaimers…

The current data set represents 17,985,146 noise events from Jan 01, 2017 to Nov 11, 2025 gathered from 24 Permanent Noise Monitors.
This information is extrapolated from noise events registered by the noise monitors. It is not the same thing as official FAA data – which does not include noise.
It often overcounts events by 1-5%.
Noise monitoring is neither mandated or regulated by the FAA. The accuracy of this data is in no way guaranteed.
Certain data (particularly altitudes) were spotty in earlier years.
This information comes from the same data source as the *Port of Seattle, which will have exactly the same challenges.

Terminology

Noise is annoying. Measuring noise is annoying, complicated, and imperfect. But we have to agree on some form of measurements if we ever hope to regulate noise. Here are ones that deserve an explanation.

SEL: the reports on this page total up thousands of SEL – individual events (an aircraft flies over a noise monitor at one moment in time). SEL events are not flights. One flight may be detected by as many as five or even six noise monitors on arrival or departure. The grand total of SEL events for any time will be far greater than the number of operations

LEQ: This is an average of SEL events over a period of time. It could be 24 hours (a day) or it could be other time frames depending on what you are studying. You can get close to that by running these reports. LEQ is often used in aviation for short-term studies, such as comparing different noise events over a day, week, or even hour. Or analyzing temporary changes due to construction or unusual flight operations. We don’t talk about LEQ too much because the FAA (and we) think it under-represents community concerns. So they do not use it in their regulations. But we track it because in Europe they do use LEQ to regulate noise.

Penalty Events: When it comes to averages, you will hear much more about something called DNL65 because it determines who gets sound insulation. DNL65 is like LEQ – a way to assign a single number to an average of noise events per day. But DNL65 adds a 10 dB penalty to nighttime noise between 10PM and 7AM. (So, if an aircraft flying over your head at 2AM reads as ’80 decibels’, it gets calculated as 90 decibels). This is supposed to account for increased sensitivity during sleep hours. So, our reports track events within that penalty period.

Fly Quiet Events: Our reports also track Fly Quiet events – which are between midnight at 5AM. This is not an official term, we invented it. However, we think it is very important. For many decades, many airports have been attempting to obtain voluntary compliance from airlines either to not fly during that penalty period or to ‘fly quiet’, ie. shift to quieter aircraft. These programs have had their ups and downs because they are voluntary. There is nothing an airport can do to alter an airlines’ schedule, compel them to use particular aircraft, or even enact quieter departure or arrival procedures. Sea-Tac Airport’s Fly Quiet program is only from 12AM to 5AM. Note that this omits four hours from the DNL65 noise penalty – 10PM to 7AM. Why? Because 10PM at night and 6AM in the morning are prime time for many carriers – especially to Asia. And adding new routes to Asia is one of Sea-Tac airport’s primary goals. (Why do you think they built the International Arrivals Facility?) In addition to the fact that a five hour window is unhealthy, it’s important to note how busy the hours are immediately before and after.

*Their system is based on work we originally began in 2016, with the assistance of former Commission President Tom Albro and Acting Director Dave Soike. The Port now publishes the same data via their Tableau site. We’re both using the same data and both sites will have the same limitations.