Daily Air Quality Index summaries from EPA monitors in Oconee, South Carolina, 1989–2019.
79%
Good days in 2019
37
Median daily AQI, 2019
0
Days above 100 in 2019
307
Days with an AQI in 2019 (of 365)
In 2019, EPA reported a daily Air Quality Index (AQI) for Oconee, South Carolina on 307 days. 241 of those days (79%) were in the Good range, and the median daily AQI was 37. That median is lower than the typical monitored county in South Carolina (median 42 across 11 counties), and lower than the typical monitored U.S. county (41). The main pollutant was fine particles (PM2.5) on 238 days. Across the years with fuller monitoring, the share of Good days rose: an average of 77% in 1989–1991 versus 80% in 2017–2019.
The most recent year with data for this county is 2019; EPA's files for 2020–2025 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, 2019
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)
238
78%
Ozone
69
22%
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
2019
307
241
66
0
0
0
0
37
55
74
PM2.5
2018
348
273
75
0
0
0
0
35
56
97
PM2.5
2017
360
295
65
0
0
0
0
39
53
84
Ozone
2016
349
276
71
2
0
0
0
43
56
133
Ozone
2015
358
325
33
0
0
0
0
37
49
74
Ozone
2014
265
188
77
0
0
0
0
41
60
90
Ozone
2013
145
144
1
0
0
0
0
36
45
67
Ozone
2012
176
147
29
0
0
0
0
42
58
97
Ozone
2011
272
182
88
2
0
0
0
44
66
110
Ozone
2010
354
276
76
2
0
0
0
41
61
119
Ozone
2009
361
291
69
1
0
0
0
39
58
101
Ozone
2008
362
264
92
6
0
0
0
43
67
126
Ozone
2007
361
226
128
6
1
0
0
45
77
161
Ozone
2006
360
255
105
0
0
0
0
44
67
96
Ozone
2005
359
258
92
8
1
0
0
42
74
156
Ozone
2004
356
260
89
7
0
0
0
42
72
147
Ozone
2003
356
242
100
14
0
0
0
42
78
140
Ozone
2002
342
209
103
24
6
0
0
45
93
179
Ozone
2001
363
231
108
24
0
0
0
46
87
150
Ozone
2000
316
182
112
21
1
0
0
45
92
151
Ozone
1999
359
192
125
37
5
0
0
48
105
169
Ozone
1998
359
258
65
28
8
0
0
42
101
187
Ozone
1997
324
213
89
22
0
0
0
44
90
143
Ozone
1996
348
270
69
9
0
0
0
42
74
129
Ozone
1995
351
262
80
8
1
0
0
41
77
151
Ozone
1994
328
253
64
9
2
0
0
41
77
161
Ozone
1993
357
289
58
8
2
0
0
39
71
179
Ozone
1992
346
309
33
4
0
0
0
34
54
115
Ozone
1991
316
276
37
2
1
0
0
34
58
190
Ozone
1990
338
222
93
23
0
0
0
44
93
126
Ozone
1989
152
119
28
5
0
0
0
36
77
136
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.
