Bad Air Days in Chatham County, Georgia: under 1 a Year

under 1 bad air day a year

Fewer bad air days than most monitored US counties. Ranked 723 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly particles: smoke and dust (88% particle days).

The bad-air season here

Most bad days here fall in November and July and February and June 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.

The worst days on file

In 2000 to 2009 this county averaged 5 bad days a year; in 2016 to 2025, under 1. The air has improved. The worst recent year was 2016, with 3 bad days on 365 monitored days.

Date	AQI	Main pollutant
2016-11-16	143	PM2.5
2016-11-17	140	PM2.5
2020-06-27	131	PM2.5
2024-02-02	130	PM2.5
2023-07-18	108	Ozone

An ordinary day in Chatham

Across 3,571 monitored days from 2016 to 2025, the air in Chatham County rated Good on 60% of them, less often than the 72% typical of monitored counties, and Moderate on 40%. The median day sat at AQI 46; one day in ten went above 60.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)83%2,973 days
ozone17%598 days

Chatham County by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	365	214	151	0	0	47	90
2024	365	232	132	1	0	44	130
2023	352	197	153	2	0	48	108
2022	335	199	136	0	0	46	97
2021	363	176	186	1	0	51	103
2020	365	232	132	1	0	46	131
2019	335	204	131	0	0	46	87
2018	363	232	131	0	0	44	77
2017	363	228	135	0	0	45	79
2016	365	234	128	3	0	44	143
2015	365	238	127	0	0	44	77
2014	333	144	189	0	0	52	80
2013	357	217	140	0	0	46	90
2012	366	178	187	1	0	51	107
2011	364	150	204	10	2	53	163
2010	364	154	210	0	0	52	100

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

Georgia 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.