Bad Air Days in Lexington County, South Carolina: under 1 a Year

under 1 bad air day a year

Rare: among the cleanest-air counties EPA monitors. Ranked 798 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly particles: smoke and dust (100% particle days).

The bad-air season here

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

What to buy, and what not to

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.

The worst days on file

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 2016, with 2 bad days on 360 monitored days.

Date	AQI	Main pollutant
2016-11-15	171	PM2.5
2016-11-16	156	PM2.5
2020-06-27	111	PM2.5
2021-07-31	102	PM2.5
2021-12-05	94	PM2.5

The air on a normal day

Across 2,676 monitored days from 2016 to 2023, the air in Lexington County rated Good on 64% of them, less often than the 72% typical of monitored counties, and Moderate on 36%. The median day sat at AQI 43; one day in ten went above 59.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)95%2,546 days
coarse dust (PM10)5%130 days

Year by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2023	149	96	53	0	0	41	77
2022	363	263	100	0	0	39	75
2021	358	199	158	1	0	46	102
2020	365	263	101	1	0	39	111
2019	365	230	135	0	0	44	69
2018	362	234	128	0	0	43	93
2017	354	220	134	0	0	44	85
2016	360	199	159	2	2	47	171
2015	365	202	163	0	0	47	92
2014	364	184	180	0	0	50	74
2013	365	201	164	0	0	47	82
2012	366	147	219	0	0	52	92
2011	365	119	246	0	0	55	96
2010	365	131	234	0	0	54	90

Nearby counties on file

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.