Bad Air Days in Kings County, California: 49 a Year

49 bad air days a year

Among the worst tenth of monitored US counties. Ranked 9 of 996 monitored counties, where 1 is worst.

What makes them bad: a mix of particles and ozone (56% particle days).

The bad-air season here

Most bad days here fall in November and August and September and December and October. Averaged over 2016 to 2025.

What actually helps here

Particles (wildfire smoke, dust) cause enough bad days here to matter. A HEPA purifier sized to your bedroom removes them; run it with windows shut on bad days.
Upgrade the furnace or AC filter to MERV 13 so the whole house is filtered, not just one room.
With this many bad days, whole-home filtration is worth an HVAC contractor quote.
Ozone drives many bad days here. Purifiers and filters do not remove ozone, so do not buy one for that. Ozone peaks on hot afternoons: exercise outside in the morning.
Sign up for EnviroFlash ozone alerts for this area during the worst months.

The worst days on file

In 2000 to 2009 this county averaged 88 bad days a year; in 2016 to 2025, 49. The air has improved. The worst recent year was 2016, with 74 bad days on 366 monitored days.

Date	AQI	Main pollutant
2021-10-11	685	PM10
2020-09-08	548	PM10
2019-10-27	508	PM10
2019-11-25	350	PM10
2020-08-22	222	PM2.5

An ordinary day in Kings

Across 3,653 monitored days from 2016 to 2025, the air in Kings County rated Good on 25% of them, less often than the 72% typical of monitored counties, and Moderate on 62%. The median day sat at AQI 65; one day in ten went above 108.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)44%1,599 days
ozone42%1,550 days
coarse dust (PM10)14%504 days

Kings County by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	365	126	228	11	0	57	133
2024	366	100	231	35	2	60	156
2023	365	124	213	28	0	58	148
2022	365	71	244	50	2	69	187
2021	365	84	230	51	11	64	685
2020	366	76	220	70	16	70	548
2019	365	123	201	41	4	58	508
2018	365	68	239	58	9	70	190
2017	365	82	212	71	21	72	192
2016	366	61	231	74	3	72	156
2015	365	72	223	70	10	74	182
2014	365	69	219	77	25	71	180
2013	365	57	213	95	15	77	204
2012	366	93	207	66	6	68	172
2011	365	78	205	82	15	73	185
2010	365	30	252	83	18	72	208

*2025 may be a partial year in EPA's file.

California compared

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, and on why a purifier does not touch ozone in smoke vs ozone.