Bad Air Days in Los Alamos County, New Mexico

Not enough data

EPA monitors in Los Alamos County ran on too few days between 2016 and 2025 to give a fair yearly count (about 31% of days covered). Neighbouring counties below are a better guide.

What to buy, and what not to

EPA monitors here ran too few days to give a fair yearly count. Use AirNow for today's air.

The worst days on file

The worst recent year was 2022, with 1 bad day on 118 monitored days.

Date	AQI	Main pollutant
2021-08-08	109	PM2.5
2022-05-02	103	PM2.5
2020-08-22	58	PM2.5
2021-08-02	58	PM2.5
2022-04-29	58	PM2.5

An ordinary day in Los Alamos

Across 1,145 monitored days from 2016 to 2025, the air in Los Alamos 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 13; one day in ten went above 28.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)100%1,145 days

Every recent year on file

Year	Days monitored	Good	Moderate	Over 100	Median AQI	Highest AQI
2025*	82	82	0	0	13	42
2024	116	116	0	0	14	41
2023	121	121	0	0	14	50
2022	118	112	5	1	14	103
2021	119	115	3	1	14	109
2020	117	113	4	0	13	58
2019	117	117	0	0	12	42
2018	120	120	0	0	13	43
2017	116	115	1	0	12	54
2016	119	119	0	0	11	32
2015	114	114	0	0	13	44
2014	117	117	0	0	14	43
2013	121	119	2	0	14	58
2012	115	115	0	0	19	48
2011	110	103	7	0	14	93
2010	112	112	0	0	13	39

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

Elsewhere in New Mexico

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.