Bad Air Days in Kauai County, Hawaii: 0 a Year

0 bad air days a year

Rare: among the cleanest-air counties EPA monitors. Ranked 961 of 996 monitored counties, where 1 is worst.

Is a purifier worth it here?

Bad air days are rare here. A standard furnace filter is enough; no purifier needed for outdoor air.
On the odd bad day, check AirNow and keep windows shut.

Better or worse than it was

Date	AQI	Main pollutant
2019-03-11	70	PM2.5
2016-01-14	59	PM2.5
2017-01-12	59	PM2.5
2016-01-13	57	PM2.5
2016-01-27	56	PM2.5

Most days, not the worst ones

Across 2,254 monitored days from 2016 to 2022, the air in Kauai County rated Good on 99% of them, more often than the 72% typical of monitored counties, and Moderate on 1%. The median day sat at AQI 16; one day in ten went above 33.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)79%1,770 days
nitrogen dioxide21%484 days

Every recent year on file

Year	Days monitored	Good	Moderate	Median AQI	Highest AQI
2022	90	90	0	13	38
2021	364	364	0	17	47
2020	365	361	4	15	52
2019	363	361	2	16	70
2018	355	350	5	18	56
2017	359	353	6	15	59
2016	358	352	6	17	59
2015	362	348	14	17	59
2014	341	322	19	23	61
2013	365	351	14	19	58
2012	365	293	72	36	64
2011	274	255	19	23	64

Elsewhere in Hawaii

Hawaii County2/yr
Maui Countyunder 1/yr
Honolulu Countyunder 1/yr

How this is counted

A bad air day is a day the county's daily AQI from EPA AirData went above 100, the level where EPA tells children, older adults and people with asthma or heart disease to cut back outdoors. Monitors do not run every day, so yearly counts are scaled to 365 days. This is the record, not today's air: for that, check AirNow. More on the method in how the county numbers are made, on the AQI 100 line in what counts as a bad air day.