Daily Air Quality Index summaries from EPA monitors in Hampton City, Virginia, 1980–2025.
83%
Good days in 2025
38
Median daily AQI, 2025
1
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 Hampton City, Virginia on 365 days. 303 of those days (83%) were in the Good range, and the median daily AQI was 38. That median is about the same as the typical monitored county in Virginia (median 37 across 25 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 184 days. Across the years with fuller monitoring, the share of Good days rose: an average of 67% in 1980–1982 versus 76% in 2023–2025.
Years with fewer than 120 monitored days (2009) 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)
184
50%
Ozone
178
49%
Nitrogen dioxide (NO₂)
2
1%
Carbon monoxide (CO)
1
<1%
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
303
61
1
0
0
0
38
53
105
PM2.5
2024
366
293
73
0
0
0
0
39
55
90
PM2.5
2023
365
241
122
1
1
0
0
43
63
174
PM2.5
2022
363
280
83
0
0
0
0
41
55
77
PM2.5
2021
365
263
102
0
0
0
0
42
56
95
PM2.5
2020
366
316
50
0
0
0
0
37
52
68
PM2.5
2019
364
283
81
0
0
0
0
42
55
84
PM2.5
2018
362
298
64
0
0
0
0
39
54
97
PM2.5
2017
365
297
68
0
0
0
0
40
55
97
Ozone
2016
362
304
56
2
0
0
0
38
53
133
PM2.5
2015
365
274
91
0
0
0
0
40
61
90
PM2.5
2014
364
268
96
0
0
0
0
41
58
97
PM2.5
2013
359
265
92
2
0
0
0
39
58
105
PM2.5
2012
366
229
131
5
1
0
0
45
64
190
PM2.5
2011
365
238
117
10
0
0
0
43
71
144
PM2.5
2010
274
176
88
7
3
0
0
45
84
179
Ozone
2009
99
89
10
0
0
0
0
5
52
68
CO
2008
365
249
103
12
1
0
0
38
77
156
Ozone
2007
365
259
94
10
2
0
0
39
71
166
Ozone
2006
365
249
104
12
0
0
0
42
74
122
Ozone
2005
365
236
116
13
0
0
0
41
77
136
Ozone
2004
366
258
102
6
0
0
0
37
75
150
Ozone
2003
363
254
98
9
1
1
0
39
71
207
Ozone
2002
365
235
98
19
11
2
0
42
97
213
Ozone
2001
362
235
108
16
3
0
0
39
83
182
Ozone
2000
366
238
108
18
2
0
0
40
87
156
Ozone
1999
301
192
73
25
9
2
0
44
108
203
Ozone
1998
236
127
70
29
10
0
0
48
119
179
Ozone
1997
199
114
44
29
12
0
0
45
136
195
Ozone
1996
235
149
66
18
2
0
0
44
100
156
Ozone
1995
238
161
51
25
1
0
0
44
101
151
Ozone
1994
237
149
66
20
2
0
0
44
100
179
Ozone
1993
233
127
66
31
7
2
0
48
122
219
Ozone
1992
237
158
56
20
2
1
0
42
100
206
Ozone
1991
236
149
55
29
3
0
0
45
119
172
Ozone
1990
315
236
57
20
2
0
0
40
87
159
Ozone
1989
357
281
61
12
3
0
0
33
77
166
Ozone
1988
356
271
53
17
12
3
0
35
97
205
Ozone
1987
363
254
63
35
11
0
0
38
115
185
Ozone
1986
363
262
66
29
5
1
0
34
100
204
Ozone
1985
361
249
80
28
3
1
0
38
100
204
Ozone
1984
329
254
57
16
2
0
0
36
87
179
Ozone
1983
357
257
52
30
16
2
0
36
119
215
Ozone
1982
353
269
59
15
10
0
0
34
90
195
Ozone
1981
350
264
59
23
4
0
0
36
90
187
Ozone
1980
261
131
78
38
13
1
0
49
122
201
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 Virginia with a similar median AQI in 2025
