Daily Air Quality Index summaries from EPA monitors in Smith, Texas, 1990–2025.
90%
Good days in 2025
35
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 Smith, Texas on 365 days. 330 of those days (90%) were in the Good range, and the median daily AQI was 35. That median is lower than the typical monitored county in Texas (median 43.5 across 44 counties), and lower than the typical monitored U.S. county (40). The main pollutant was ozone on 355 days. Across the years with fuller monitoring, the share of Good days rose: an average of 68% in 1994–1996 versus 86% in 2023–2025.
Years with fewer than 120 monitored days (1990, 1991, 1992, 1993) 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
Ozone
355
97%
Nitrogen dioxide (NO₂)
10
3%
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
330
35
0
0
0
0
35
50
93
Ozone
2024
363
314
48
1
0
0
0
39
61
105
Ozone
2023
364
296
64
4
0
0
0
38
67
119
Ozone
2022
363
289
68
6
0
0
0
40
64
122
Ozone
2021
361
333
28
0
0
0
0
35
48
100
Ozone
2020
366
352
14
0
0
0
0
33
46
84
Ozone
2019
364
326
37
1
0
0
0
36
51
133
Ozone
2018
364
324
38
2
0
0
0
33
54
112
Ozone
2017
364
336
28
0
0
0
0
37
49
90
Ozone
2016
366
344
21
1
0
0
0
37
48
101
Ozone
2015
365
319
45
1
0
0
0
33
54
108
Ozone
2014
365
329
36
0
0
0
0
34
50
100
Ozone
2013
357
306
47
4
0
0
0
38
61
126
Ozone
2012
365
286
72
7
0
0
0
40
71
147
Ozone
2011
363
268
76
19
0
0
0
42
87
150
Ozone
2010
365
297
62
6
0
0
0
38
67
115
Ozone
2009
364
297
62
5
0
0
0
38
61
143
Ozone
2008
364
304
56
3
1
0
0
38
61
190
Ozone
2007
353
286
54
13
0
0
0
37
74
143
Ozone
2006
365
264
66
33
2
0
0
42
100
159
Ozone
2005
365
247
86
31
1
0
0
43
100
156
Ozone
2004
366
265
65
35
1
0
0
39
100
164
Ozone
2003
360
254
83
22
1
0
0
42
87
154
Ozone
2002
364
281
63
17
3
0
0
40
84
161
Ozone
2001
363
264
80
18
1
0
0
41
84
151
Ozone
2000
354
244
76
29
5
0
0
42
100
161
Ozone
1999
359
236
67
38
17
1
0
43
119
216
Ozone
1998
351
250
72
22
7
0
0
39
93
185
Ozone
1997
307
205
59
38
5
0
0
41
112
166
Ozone
1996
348
225
81
37
5
0
0
44
105
179
Ozone
1995
337
213
76
36
12
0
0
44
122
187
Ozone
1994
170
129
27
13
1
0
0
32
97
166
Ozone
1993
55
54
1
0
0
0
0
14
28
51
PM10
1992
53
52
1
0
0
0
0
16
26
61
PM10
1991
58
58
0
0
0
0
0
18
26
46
PM10
1990
46
46
0
0
0
0
0
18
29
45
PM10
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 Texas with a similar median AQI in 2025
