Spartanburg County, South Carolina air quality history
Daily Air Quality Index summaries from EPA monitors in Spartanburg, South Carolina, 1990–2025.
55%
Good days in 2025
48
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 Spartanburg, South Carolina on 365 days. 201 of those days (55%) were in the Good range, and the median daily AQI was 48. That median is higher than the typical monitored county in South Carolina (median 43 across 13 counties), and higher than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 236 days. Across the years with fuller monitoring, the share of Good days fell: an average of 72% in 1990–1992 versus 51% in 2023–2025.
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)
236
65%
Ozone
129
35%
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
201
164
0
0
0
0
48
62
93
PM2.5
2024
363
188
171
4
0
0
0
49
71
112
PM2.5
2023
365
166
194
5
0
0
0
51
71
136
PM2.5
2022
363
206
157
0
0
0
0
47
61
87
PM2.5
2021
354
201
152
1
0
0
0
46
64
119
PM2.5
2020
366
232
132
2
0
0
0
45
58
112
PM2.5
2019
348
206
140
2
0
0
0
45
61
105
PM2.5
2018
365
223
142
0
0
0
0
44
60
77
PM2.5
2017
351
197
153
1
0
0
0
48
61
108
PM2.5
2016
351
161
188
2
0
0
0
52
64
126
PM2.5
2015
364
187
177
0
0
0
0
49
67
97
PM2.5
2014
364
180
183
1
0
0
0
51
63
116
PM2.5
2013
356
182
173
1
0
0
0
49
64
105
PM2.5
2012
359
140
219
0
0
0
0
53
66
93
PM2.5
2011
365
122
230
12
1
0
0
57
84
156
PM2.5
2010
361
122
221
18
0
0
0
56
90
140
PM2.5
2009
364
149
214
1
0
0
0
53
68
101
PM2.5
2008
359
115
218
23
3
0
0
57
97
172
PM2.5
2007
356
107
228
19
2
0
0
59
92
154
PM2.5
2006
355
102
223
27
3
0
0
60
97
172
PM2.5
2005
354
85
237
30
2
0
0
60
97
151
PM2.5
2004
359
97
239
21
2
0
0
59
88
156
PM2.5
2003
359
98
244
15
2
0
0
58
86
172
PM2.5
2002
358
103
199
40
15
1
0
58
126
202
PM2.5
2001
360
89
242
22
7
0
0
59
97
172
PM2.5
2000
366
74
247
36
9
0
0
62
108
187
PM2.5
1999
352
81
221
40
9
1
0
63
115
205
PM2.5
1998
327
225
60
32
10
0
0
41
115
195
Ozone
1997
359
249
75
31
4
0
0
41
100
169
Ozone
1996
340
234
75
27
4
0
0
40
100
200
Ozone
1995
339
238
71
26
4
0
0
37
100
195
Ozone
1994
294
217
60
14
3
0
0
38
87
172
Ozone
1993
323
214
82
25
2
0
0
39
97
185
Ozone
1992
298
261
30
6
1
0
0
30
61
151
Ozone
1991
349
238
85
24
2
0
0
40
97
172
Ozone
1990
244
145
73
25
1
0
0
45
101
169
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 Carolina with a similar median AQI in 2025
