Texas · County air quality · 2025

Webb County, Texas

Median AQI 51 (Moderate). 49.9% of monitored days rated Good, direct from EPA Air Quality System stations.

51
Median AQI
49.9%
Good-air days
0
Unhealthy days
6%
Cleaner than US counties

Webb County's 2025 annual median AQI is 51 (Moderate), with 49.9% Good days

According to the U.S. EPA Air Quality System, Webb County, Texas posted a 2025 median AQI of 51 (Moderate) across 365 monitored days, with 49.9% rated Good and 0 unhealthy or worse. This is an annual comparison, not today's advisory.

Data source EPA Air Quality System (AQS)

Cleaner than US
Webb County's 49.9% Good-day share places it cleaner than 6% of US counties in 2025.
Closest median-AQI peer
Davidson County (45.8% Good, median AQI 51) is the closest nationwide median-AQI peer to Webb County.
2020–2025 trend
Webb County's floor-qualifying Good-day share is worsening from 2020 to 2025 (59.3% → 49.9%).
Median AQI
Median AQI: 51

According to the 2025 EPA AQS county release on PlainAirData, Webb County, Texas ranks #892 of 951 by median AQI (51) and #892 by good-day share (49.9%). Ponce County, Puerto Rico is #1 of 951 by median AQI (3, 91.4% Good days) at good-day-share #159 ≠ largest of 7 at 100.0% Good days #1 by good-day share (100.0%, median AQI 9) at median-AQI #7.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Webb County's Good-day share fell from 57.7% to 49.9% between the 2024 and 2025 EPA annual releases, a change of -7.8 percentage points.
  • Webb County's median AQI rose from 45 to 51 between the 2024 and 2025 EPA annual releases, a change of +6 points.

Compared against 366 monitored days in 2024 and 365 in 2025. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

Data updated August 2026

Webb County AQI category distribution Stacked-segment bar showing the share of monitored days that fell in each EPA AQI category, Good, Moderate, USG, Unhealthy, Very Unhealthy, Hazardous, with median AQI marker. AQI category distribution 365 monitored days G M Median AQI 51 0 50 100 150 200 300 500 Webb County
  • Good · 182 d · 49.9%
  • Moderate · 178 d · 48.8%
  • USG · 5 d · 1.4%

How did Webb County's air break down in 2025?

Across 365 monitored days, 182 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 121 (USG).

EPA AQS →
Webb County, Good days share 49.9%
National avg

Share of monitored days at AQI 0-50 (Good band).

Webb County, Unhealthy-or-worse share 0.0%
National avg

Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).

Where Webb County sits nationally

COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Webb County's Good-day share is 49.9% - cleaner than 6% of that comparison set.

Webb County Good-day share vs. every US county

Share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release

49.9% 6th percentile higher than 6% of 951 US counties

0.0%–5.0%: 0 US counties (0%). Below this entry. 5.0%–10.0%: 1 US counties (0%). Below this entry. 10.0%–15.0%: 4 US counties (0%). Below this entry. 15.0%–20.0%: 4 US counties (0%). Below this entry. 20.0%–25.0%: 1 US counties (0%). Below this entry. 25.0%–30.0%: 5 US counties (1%). Below this entry. 30.0%–35.0%: 9 US counties (1%). Below this entry. 35.0%–40.0%: 4 US counties (0%). Below this entry. 40.0%–45.0%: 16 US counties (2%). Below this entry. 45.0%–50.0%: 16 US counties (2%). This entry sits in this band. 50.0%–55.0%: 32 US counties (3%). Above this entry. 55.0%–60.0%: 50 US counties (5%). Above this entry. 60.0%–65.0%: 77 US counties (8%). Above this entry. 65.0%–70.0%: 93 US counties (10%). Above this entry. 70.0%–75.0%: 109 US counties (11%). Above this entry. 75.0%–80.0%: 114 US counties (12%). Above this entry. 80.0%–85.0%: 123 US counties (13%). Above this entry. 85.0%–90.0%: 99 US counties (10%). Above this entry. 90.0%–95.0%: 117 US counties (12%). Above this entry. 95.0%–100.0%: 70 US counties (7%). Above this entry. 100.0%–105.0%: 7 US counties (1%). Above this entry. This county 0.0% 100% every floor-qualified US county, bucketed by value

Each bar is a band; taller bars hold more US counties. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source U.S. Environmental Protection Agency, Air Quality System (AQS) · 2025

Pollutant Breakdown

Days where each pollutant was the primary driver of AQI readings in Webb County.

Webb County, Texas criteria pollutant distribution Stratified-band visualization showing the share of monitored days each criteria pollutant (PM2.5, PM10, O3, NO2, CO) was the primary AQI driver. PM2.5 · 58.9% Ozone · 38.9% 0% 25% 50% 75% 100% Webb County, Texas · 365 monitored days Criteria pollutant column
  • PM2.5 · 215 days · 58.9%
  • Ozone · 142 days · 38.9%
  • PM10 · 8 days · 2.2%

2024 daily-monitor rhythm in Webb County

Month-by-month median AQI from EPA day-level county monitors (366 reported days in 2024). May posted the highest typical readings (median AQI 84, peak 129); Dec was cleanest at median 35. Summer months (Jun–Aug) averaged median AQI 47 vs 40 in Dec–Feb.

0 20 40 60 80 100 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 41 44 51 64 84 45 56 40 42 42 43 35
Webb County median daily AQI by calendar month (2024, EPA daily county file)

Five-year seasonal record

EPA day-level county files · 2020–2024

1,823 daily readings show a recurring local pattern: May has the highest matched-month median AQI (59), while Nov is lowest (38). Each cell is that month’s median daily AQI, not a current-air forecast.

JanFebMarAprMayJunJulAugSepOctNovDec
2020 364357584751604649444243
2021 394852565450555151443851
2022 444348605853543733373135
2023 414356525355415644353637
2024 414451648445564042424335

Lower AQI is better. The colors summarize EPA AQI bands; gaps mean the county had no day-level record for that month.

Health Impact Assessment

Poor

Webb County's air quality is rated Poor based on 49.9% good air days. No unhealthy air days were recorded in 2025.

Air quality was acceptable on 49.9% of monitored days in 2025, with a median AQI of 51. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.

The dominant pollutant is PM2.5, driving AQI on 215 of 365 monitored days.

5-Year Air Quality Trend

Air quality is worsening in Webb County. Highest Good-day share: 2023 (62.2%, 227 of 365 monitored days).

Year Good Moderate USG Unhealthy Median AQI
2020 217 146 2 1 47
2021 197 168 0 0 48
2022 215 144 2 0 45
2023 227 133 5 0 44
2024 211 140 15 0 45
2025 182 178 5 0 51

How does Webb County compare?

How Webb County compares

Good-day share worse than typical
Webb County 49.9%
Davidson County, North Carolina 45.8%
Typical US county 76.0%
Median AQI worse than typical
Webb County 51
Davidson County, North Carolina 51
Typical US county 39
Unhealthy days / yr better than typical
Webb County 0
Davidson County, North Carolina 0
Typical US county 1

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.

Informational only, not professional advice. Data from EPA AQS. See our disclaimer. Spotted a figure that looks wrong? Report a correction.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Webb County, Texas · 2020–2025

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Download this county's annual AQI row as CSV , with the same EPA fields and denominator shown on this page.

Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.