Daily Air Quality Index summaries from EPA monitors in Hancock, Indiana, 1980–2015.
90%
Good days in 2015
34
Median daily AQI, 2015
0
Days above 100 in 2015
183
Days with an AQI in 2015 (of 365)
In 2015, EPA reported a daily Air Quality Index (AQI) for Hancock, Indiana on 183 days. 165 of those days (90%) were in the Good range, and the median daily AQI was 34. That median is lower than the typical monitored county in Indiana (median 43 across 37 counties), and lower than the typical monitored U.S. county (41). The main pollutant was ozone on 183 days. Across the years with fuller monitoring, the share of Good days rose: an average of 72% in 1980–1982 versus 93% in 2013–2015.
EPA did not report an AQI for every day of 2015 here (183 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 2015; EPA's files for 2016–2025 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, 2015
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
183
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
2015
183
165
18
0
0
0
0
34
50
97
Ozone
2014
183
181
2
0
0
0
0
34
45
67
Ozone
2013
180
163
17
0
0
0
0
40
50
77
Ozone
2012
182
160
21
1
0
0
0
40
54
105
Ozone
2011
182
139
41
2
0
0
0
43
74
108
Ozone
2010
183
120
59
4
0
0
0
45
80
105
Ozone
2009
181
140
40
1
0
0
0
44
71
122
Ozone
2008
183
117
60
6
0
0
0
47
84
126
Ozone
2007
182
94
60
27
1
0
0
49
108
172
Ozone
2006
182
122
47
13
0
0
0
45
90
136
Ozone
2005
182
103
53
25
1
0
0
48
105
156
Ozone
2004
183
129
48
6
0
0
0
44
87
122
Ozone
2003
183
98
69
11
4
1
0
48
97
201
Ozone
2002
183
95
50
20
16
2
0
49
136
202
Ozone
2001
183
99
51
25
8
0
0
49
119
192
Ozone
2000
183
123
47
9
4
0
0
45
87
182
Ozone
1999
182
79
56
35
12
0
0
54
136
185
Ozone
1998
135
42
57
24
11
1
0
71
147
203
Ozone
1997
182
108
51
16
7
0
0
46
108
190
Ozone
1996
181
92
50
29
9
1
0
50
129
204
Ozone
1995
182
101
51
23
7
0
0
47
115
197
Ozone
1994
181
88
44
34
15
0
0
51
140
185
Ozone
1993
183
84
65
28
6
0
0
54
126
172
Ozone
1992
181
125
43
11
2
0
0
44
87
172
Ozone
1991
169
105
38
21
4
1
0
45
115
202
Ozone
1990
214
158
33
17
6
0
0
38
105
185
Ozone
1989
197
126
47
20
4
0
0
45
108
172
Ozone
1988
209
113
49
17
29
1
0
48
164
202
Ozone
1987
143
82
32
25
4
0
0
47
126
174
Ozone
1986
128
70
39
16
3
0
0
49
115
154
Ozone
1985
126
71
40
13
2
0
0
48
112
195
Ozone
1984
268
194
45
23
5
1
0
36
101
202
Ozone
1983
299
229
38
25
6
1
0
32
101
206
Ozone
1982
357
276
45
27
8
1
0
35
101
203
Ozone
1981
310
238
36
27
9
0
0
32
105
197
Ozone
1980
184
116
26
29
7
6
0
39
136
219
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.
