Bad Air Days in Lincoln County, Wyoming: under 1 a Year

under 1 bad air day a year

Fewer bad air days than most monitored US counties. Ranked 731 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly particles: smoke and dust (63% particle days).

Which months to watch

Most bad days here fall in July and June and August and December. Averaged over 2016 to 2025.

What actually helps 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

In 2000 to 2009 this county averaged under 1 bad days a year; in 2016 to 2025, under 1. Not much has changed. The worst recent year was 2021, with 6 bad days on 365 monitored days.

Date	AQI	Main pollutant
2017-12-07	208	PM10
2021-07-26	126	Ozone
2022-06-30	118	PM10
2021-07-24	115	Ozone
2021-08-07	109	PM2.5

Most days, not the worst ones

Across 3,653 monitored days from 2016 to 2025, the air in Lincoln County rated Good on 93% of them, more often than the 72% typical of monitored counties, and Moderate on 7%. The median day sat at AQI 23; one day in ten went above 42.

The pollutant setting the AQI on an ordinary day here:

coarse dust (PM10)72%2,624 days
ozone26%955 days
fine particles (PM2.5)1%51 days
nitrogen dioxide1%23 days

Year by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	365	361	4	0	0	10	77
2024	366	340	26	0	0	31	77
2023	365	298	67	0	0	44	97
2022	365	321	43	1	0	43	118
2021	365	297	62	6	0	30	126
2020	366	357	9	0	0	15	71
2019	365	364	1	0	0	12	56
2018	365	343	22	0	0	16	82
2017	365	348	16	1	1	14	208
2016	366	363	3	0	0	13	69
2015	365	355	10	0	0	13	96
2014	365	358	7	0	0	14	69
2013	365	338	26	1	1	19	160
2012	366	315	45	6	2	19	186
2011	365	341	24	0	0	15	89
2010	362	341	21	0	0	17	88

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

Elsewhere in Wyoming

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.