Daily Air Quality Index summaries from EPA monitors in Webb, Texas, 1988–2025.
50%
Good days in 2025
51
Median daily AQI, 2025
5
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 Webb, Texas on 365 days. 182 of those days (50%) were in the Good range, and the median daily AQI was 51. That median is higher than the typical monitored county in Texas (median 43.5 across 44 counties), and higher than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 215 days. Across the years with fuller monitoring, the share of Good days fell: an average of 88% in 1996–1998 versus 57% in 2023–2025.
Years with fewer than 120 monitored days (1990, 1991, 1992, 1993, 1994, 1995…) 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)
215
59%
Ozone
142
39%
Coarse particles (PM10)
8
2%
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
182
178
5
0
0
0
51
71
121
PM2.5
2024
366
211
140
15
0
0
0
45
83
129
Ozone
2023
365
227
133
5
0
0
0
44
71
133
PM2.5
2022
361
215
144
2
0
0
0
45
69
114
PM2.5
2021
365
197
168
0
0
0
0
48
69
97
PM2.5
2020
366
217
146
2
1
0
0
47
68
163
PM2.5
2019
365
187
177
1
0
0
0
50
71
109
PM2.5
2018
313
190
121
2
0
0
0
44
67
107
PM2.5
2017
177
94
83
0
0
0
0
49
67
89
PM2.5
2016
366
222
144
0
0
0
0
46
65
97
PM2.5
2015
365
192
173
0
0
0
0
49
67
95
PM2.5
2014
365
165
200
0
0
0
0
52
66
84
PM2.5
2013
365
209
153
3
0
0
0
46
69
122
PM2.5
2012
346
155
190
1
0
0
0
52
66
103
PM2.5
2011
350
164
183
3
0
0
0
52
71
104
PM2.5
2010
365
200
165
0
0
0
0
48
67
100
PM2.5
2009
365
177
188
0
0
0
0
51
67
90
PM2.5
2008
366
153
210
3
0
0
0
53
71
144
PM2.5
2007
365
133
232
0
0
0
0
53
69
100
PM2.5
2006
365
124
237
3
0
0
1
54
70
383
PM2.5
2005
365
168
194
3
0
0
0
52
68
104
PM2.5
2004
366
339
27
0
0
0
0
31
47
87
Ozone
2003
365
297
65
2
1
0
0
34
60
152
Ozone
2002
365
285
78
1
1
0
0
37
58
162
Ozone
2001
365
284
80
1
0
0
0
38
58
108
Ozone
2000
366
273
89
4
0
0
0
38
64
129
Ozone
1999
365
302
63
0
0
0
0
36
57
100
Ozone
1998
364
307
54
3
0
0
0
35
61
105
Ozone
1997
342
313
26
3
0
0
0
33
49
136
Ozone
1996
138
122
16
0
0
0
0
31
53
98
Ozone
1995
36
34
2
0
0
0
0
26
48
55
PM10
1994
47
41
6
0
0
0
0
27
52
67
PM10
1993
57
54
3
0
0
0
0
26
46
53
PM10
1992
48
45
3
0
0
0
0
26
48
85
PM10
1991
51
42
9
0
0
0
0
32
54
61
PM10
1990
33
30
3
0
0
0
0
29
48
57
PM10
1989
11
10
1
0
0
0
0
31
46
59
PM10
1988
13
13
0
0
0
0
0
21
34
37
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
