Daily Air Quality Index summaries from EPA monitors in Chatham, Georgia, 1983–2025.
59%
Good days in 2025
47
Median daily AQI, 2025
0
Days above 100 in 2025
365
Days with an AQI in 2025 (of 365)
In 2025, EPA reported a daily Air Quality Index (AQI) for Chatham, Georgia on 365 days. 214 of those days (59%) were in the Good range, and the median daily AQI was 47. That median is about the same as the typical monitored county in Georgia (median 46 across 25 counties), and higher than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 307 days. Across the years with fuller monitoring, the share of Good days fell: an average of 84% in 1983–1996 versus 59% in 2023–2025.
Years with fewer than 120 monitored days (1989, 1990, 1991, 1992, 1993, 1994…) are shown in the table but left out of comparisons and trend statements.
How the days broke down each year
Each bar is one year. The colored segments show the share of monitored days that fell in each AQI category.
Good
Moderate
Unhealthy for Sensitive Groups
Unhealthy
Very Unhealthy
Hazardous
Typical and high-end AQI over time
The median is the middle day of the year. The 90th percentile is the level that only the highest 10% of days exceeded.
Median daily AQI
90th-percentile daily AQI
Main pollutant by day, 2025
On each monitored day, the AQI reflects whichever measured pollutant had the highest index. This counts how many days each pollutant set the AQI. A pollutant that was not measured here cannot appear.
Pollutant
Days as main pollutant
Share of monitored days
Fine particles (PM2.5)
307
84%
Ozone
58
16%
Year-by-year data
Annual AQI summary by year
Year
Days with AQI
Good
Moderate
Unhealthy for Sensitive Groups
Unhealthy
Very Unhealthy
Hazardous
Median AQI
90th pct.
Max AQI
Main pollutant
2025
365
214
151
0
0
0
0
47
59
90
PM2.5
2024
365
232
132
1
0
0
0
44
58
130
PM2.5
2023
352
197
153
2
0
0
0
48
63
108
PM2.5
2022
335
199
136
0
0
0
0
46
60
97
PM2.5
2021
363
176
186
1
0
0
0
51
63
103
PM2.5
2020
365
232
132
1
0
0
0
46
59
131
PM2.5
2019
335
204
131
0
0
0
0
46
60
87
PM2.5
2018
363
232
131
0
0
0
0
44
58
77
PM2.5
2017
363
228
135
0
0
0
0
45
60
79
PM2.5
2016
365
234
128
3
0
0
0
44
59
143
PM2.5
2015
365
238
127
0
0
0
0
44
60
77
PM2.5
2014
333
144
189
0
0
0
0
52
62
80
PM2.5
2013
357
217
140
0
0
0
0
46
62
90
PM2.5
2012
366
178
187
1
0
0
0
51
64
107
PM2.5
2011
364
150
204
8
2
0
0
53
76
163
PM2.5
2010
364
154
210
0
0
0
0
52
67
100
PM2.5
2009
365
160
204
1
0
0
0
52
65
115
PM2.5
2008
366
140
223
3
0
0
0
54
72
136
PM2.5
2007
365
98
260
5
2
0
0
58
76
156
PM2.5
2006
364
82
281
1
0
0
0
61
80
119
PM2.5
2005
365
92
268
5
0
0
0
58
80
138
PM2.5
2004
366
91
269
6
0
0
0
56
78
126
PM2.5
2003
364
213
147
4
0
0
0
44
72
136
PM2.5
2002
365
253
111
0
1
0
0
36
66
151
Ozone
2001
365
250
111
3
1
0
0
36
70
160
Ozone
2000
364
210
139
13
2
0
0
45
81
172
Ozone
1999
363
218
123
19
3
0
0
42
87
154
Ozone
1998
352
276
67
9
0
0
0
32
74
133
Ozone
1997
264
221
39
4
0
0
0
35
58
112
Ozone
1996
256
206
45
5
0
0
0
39
67
140
Ozone
1995
238
196
37
5
0
0
0
36
64
119
Ozone
1994
51
48
3
0
0
0
0
31
49
54
PM10
1993
49
44
5
0
0
0
0
31
51
71
PM10
1992
56
52
4
0
0
0
0
32
47
67
PM10
1991
57
51
6
0
0
0
0
32
51
60
PM10
1990
60
53
7
0
0
0
0
34
53
76
PM10
1989
58
45
13
0
0
0
0
38
56
76
PM10
1988
55
46
9
0
0
0
0
37
55
65
PM10
1987
105
90
15
0
0
0
0
32
51
66
PM10
1986
99
82
17
0
0
0
0
38
55
96
PM10
1983
171
155
15
1
0
0
0
14
49
109
CO
What this data can and can’t tell you
It is a county-level summary. EPA reports one AQI per day for the county, based on the monitors operating there. Air at a particular street, school or home can differ, especially near roads, industry or wildfire smoke.
It is not a health assessment. The AQI is EPA’s scale for communicating daily air quality. A county’s history can’t tell you what the health risk is for any particular person. For daily conditions and health guidance, see AirNow.
Rules change over time. EPA has revised AQI breakpoints, most recently for fine particles in 2024, so some year-to-year change can reflect the scale rather than the air.
Counties in Georgia with a similar median AQI in 2025
