Daily Air Quality Index summaries from EPA monitors in Yancey, North Carolina, 1992–2024.
82%
Good days in 2024
44
Median daily AQI, 2024
0
Days above 100 in 2024
204
Days with an AQI in 2024 (of 366)
In 2024, EPA reported a daily Air Quality Index (AQI) for Yancey, North Carolina on 204 days. 167 of those days (82%) were in the Good range, and the median daily AQI was 44. That median is higher than the typical monitored county in North Carolina (median 41.5 across 34 counties), and higher than the typical monitored U.S. county (41). The main pollutant was ozone on 204 days. Across the years with fuller monitoring, the share of Good days rose: an average of 41% in 1992–1994 versus 80% in 2022–2024.
EPA did not report an AQI for every day of 2024 here (204 of 366 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 2024; EPA's files for 2025–2025 contain no row for it, which usually means its monitors stopped reporting.
Years with fewer than 120 monitored days (1998) 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, 2024
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
204
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
2024
204
167
37
0
0
0
0
44
58
84
Ozone
2023
240
179
60
1
0
0
0
45
67
101
Ozone
2022
242
200
42
0
0
0
0
44
61
93
Ozone
2021
240
186
54
0
0
0
0
44
61
90
Ozone
2020
244
204
39
1
0
0
0
44
58
105
Ozone
2019
244
191
53
0
0
0
0
45
64
87
Ozone
2018
230
184
46
0
0
0
0
44
64
84
Ozone
2017
202
155
47
0
0
0
0
44
61
93
Ozone
2016
204
145
55
4
0
0
0
46
67
115
Ozone
2015
192
136
56
0
0
0
0
45
67
97
Ozone
2014
199
157
41
1
0
0
0
44
61
101
Ozone
2013
211
169
42
0
0
0
0
46
61
97
Ozone
2012
194
141
50
2
1
0
0
47
64
156
Ozone
2011
191
72
115
4
0
0
0
58
87
126
Ozone
2010
211
130
74
7
0
0
0
48
80
129
Ozone
2009
191
150
41
0
0
0
0
44
61
93
Ozone
2008
166
87
73
6
0
0
0
50
87
133
Ozone
2007
195
65
107
22
1
0
0
64
105
161
Ozone
2006
194
97
87
10
0
0
0
51
87
129
Ozone
2005
209
87
100
22
0
0
0
58
101
150
Ozone
2004
204
155
46
3
0
0
0
44
74
108
Ozone
2003
206
99
90
16
1
0
0
51
97
154
Ozone
2002
203
89
77
31
6
0
0
58
133
174
Ozone
2001
193
75
92
25
1
0
0
61
105
151
Ozone
2000
185
68
88
25
4
0
0
64
115
179
Ozone
1999
179
41
93
35
10
0
0
74
133
185
Ozone
1998
77
42
34
1
0
0
0
49
87
147
Ozone
1997
213
144
56
13
0
0
0
45
93
136
Ozone
1996
124
45
61
18
0
0
0
64
108
143
Ozone
1995
170
40
77
39
14
0
0
80
143
200
Ozone
1994
168
82
74
10
2
0
0
51
93
161
Ozone
1993
158
36
85
31
6
0
0
74
115
166
Ozone
1992
169
89
67
12
1
0
0
50
93
151
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.