Daily Air Quality Index summaries from EPA monitors in Adams, Mississippi, 1987–2011.
80%
Good days in 2011
41
Median daily AQI, 2011
1
Days above 100 in 2011
174
Days with an AQI in 2011 (of 365)
In 2011, EPA reported a daily Air Quality Index (AQI) for Adams, Mississippi on 174 days. 139 of those days (80%) were in the Good range, and the median daily AQI was 41. That median is lower than the typical monitored county in Mississippi (median 52 across 11 counties), and lower than the typical monitored U.S. county (44). The main pollutant was ozone on 174 days. Across the years with fuller monitoring, the share of Good days fell: an average of 78% in 1987–1989 versus 72% in 2009–2011.
EPA did not report an AQI for every day of 2011 here (174 of 365 days). Figures describe monitored days only; seasonal monitoring (for example, ozone measured only in warmer months) can make a county look cleaner or dirtier than a full-year record would.
The most recent year with data for this county is 2011; EPA's files for 2012–2025 contain no row for it, which usually means its monitors stopped reporting.
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, 2011
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
Ozone
174
100%
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
2011
174
139
34
1
0
0
0
41
67
101
Ozone
2010
283
185
97
1
0
0
0
44
66
119
Ozone
2009
283
202
81
0
0
0
0
41
61
93
Ozone
2008
276
180
96
0
0
0
0
44
66
97
Ozone
2007
280
178
98
4
0
0
0
45
71
119
Ozone
2006
282
162
109
11
0
0
0
48
84
136
Ozone
2005
283
142
131
10
0
0
0
50
90
126
Ozone
2004
279
172
103
4
0
0
0
45
77
119
Ozone
2003
272
157
94
18
3
0
0
46
90
161
Ozone
2002
278
173
100
5
0
0
0
45
77
147
Ozone
2001
274
164
101
9
0
0
0
46
80
119
Ozone
2000
280
120
126
28
6
0
0
54
105
179
Ozone
1999
235
92
105
37
1
0
0
58
115
174
Ozone
1998
195
106
56
30
3
0
0
49
115
159
Ozone
1997
205
100
93
10
2
0
0
51
97
156
Ozone
1996
245
155
74
15
1
0
0
44
97
151
Ozone
1995
261
201
49
10
1
0
0
39
84
169
Ozone
1994
275
239
32
4
0
0
0
35
54
140
Ozone
1993
273
223
42
8
0
0
0
37
71
129
Ozone
1992
264
223
37
4
0
0
0
37
58
126
Ozone
1991
271
234
34
3
0
0
0
36
61
108
Ozone
1990
274
220
52
2
0
0
0
39
77
105
Ozone
1989
269
224
43
1
1
0
0
34
64
192
Ozone
1988
268
196
53
15
4
0
0
41
97
161
Ozone
1987
255
196
50
9
0
0
0
40
77
126
Ozone
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.
