Daily Air Quality Index summaries from EPA monitors in Jackson, South Dakota, 1987–2025.
79%
Good days in 2025
43
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 Jackson, South Dakota on 365 days. 287 of those days (79%) were in the Good range, and the median daily AQI was 43. That median is higher than the typical monitored county in South Dakota (median 35.5 across 10 counties), and higher than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 205 days. Across the years with fuller monitoring, the share of Good days fell: an average of 93% in 1988–1990 versus 76% in 2023–2025.
Years with fewer than 120 monitored days (1995, 1996, 1997, 1998, 1999, 2001…) 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)
205
56%
Ozone
160
44%
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
287
78
0
0
0
0
43
55
85
PM2.5
2024
366
269
90
7
0
0
0
44
67
129
Ozone
2023
365
277
80
3
4
1
0
43
64
233
Ozone
2022
365
311
54
0
0
0
0
40
55
97
Ozone
2021
365
309
54
0
1
1
0
35
55
233
Ozone
2020
366
324
42
0
0
0
0
39
52
90
Ozone
2019
365
343
22
0
0
0
0
38
49
63
Ozone
2018
365
305
59
1
0
0
0
42
55
123
Ozone
2017
365
307
56
2
0
0
0
41
58
135
Ozone
2016
364
344
20
0
0
0
0
37
48
97
Ozone
2015
364
320
42
2
0
0
0
38
53
142
Ozone
2014
358
325
33
0
0
0
0
40
50
87
Ozone
2013
364
304
60
0
0
0
0
37
54
93
Ozone
2012
366
315
51
0
0
0
0
37
54
93
Ozone
2011
363
350
13
0
0
0
0
35
45
69
Ozone
2010
365
328
37
0
0
0
0
37
51
74
Ozone
2009
365
348
17
0
0
0
0
34
45
66
Ozone
2008
365
352
12
1
0
0
0
34
44
140
Ozone
2007
365
313
52
0
0
0
0
37
54
93
Ozone
2006
365
276
85
4
0
0
0
41
74
112
Ozone
2005
365
311
51
3
0
0
0
40
58
101
Ozone
2004
362
313
49
0
0
0
0
38
54
87
Ozone
2003
227
190
36
1
0
0
0
31
58
101
Ozone
2002
124
110
14
0
0
0
0
26
52
62
PM2.5
2001
118
109
9
0
0
0
0
22
49
58
PM2.5
2000
128
111
17
0
0
0
0
19
52
69
PM2.5
1999
95
92
3
0
0
0
0
18
37
60
PM2.5
1998
102
90
12
0
0
0
0
22
53
67
PM2.5
1997
103
99
4
0
0
0
0
20
39
72
PM2.5
1996
102
100
2
0
0
0
0
22
37
58
PM2.5
1995
103
97
6
0
0
0
0
20
38
59
PM2.5
1994
105
91
14
0
0
0
0
24
52
63
PM2.5
1993
103
98
5
0
0
0
0
21
37
55
PM2.5
1992
214
204
10
0
0
0
0
33
45
72
Ozone
1991
343
332
11
0
0
0
0
32
45
58
Ozone
1990
340
323
17
0
0
0
0
32
44
76
Ozone
1989
336
316
20
0
0
0
0
33
47
93
Ozone
1988
337
305
32
0
0
0
0
38
50
93
Ozone
1987
30
30
0
0
0
0
0
28
31
31
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.
Counties in South Dakota with a similar median AQI in 2025
