Median AQI
54
Moderate
Texas · County air quality · 2025
Hidalgo County, Texas
Median AQI 54 (Moderate). 36.2% of monitored days rated Good, direct from EPA Air Quality System stations.
- 54
- Median AQI
- 36.2%
- Good-air days
- 0
- Unhealthy days
- 2%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Hidalgo County's air is moderate on balance, among the most polluted counties nationally, a median AQI of 54 with 36.2% of 243 monitored days in the Good band, driven mainly by PM2.5.
- 54
- median AQI · Moderate
- 36.2%
- days rated Good
- PM2.5
- main pollutant
- 2%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 140.
Data updated July 2026
- Good · 88 d · 36.2%
- Moderate · 151 d · 62.1%
- USG · 4 d · 1.6%
How did Hidalgo County's air break down in 2025?
Across 243 monitored days, 88 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 140 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 243 days monitored. Median AQI: 54 (Moderate).
Insights: Hidalgo County, Texas. EPA monitors recorded a median Air Quality Index of 54 across 243 measured days in 2025, earning a Moderate classification and a Poor health grade. Of those days, 88 (36%) fell in the Good band (AQI 0–50), 151 (62%) registered Moderate readings, and 4 (2%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 74, while the worst single-day peak hit 140 (USG). Residents averaged about 10.9 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (197 days), Ozone (38 days), PM10 (8 days). Across the 2020–2025 trend window, good days shifted by -134 and the median AQI moved +10 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 140, usg but never Unhealthy. Nearby counties show comparable readings: Atascosa (58.0% good, AQI 45); Bell (61.3% good, AQI 47); Bexar (39.8% good, AQI 53); Bowie (57.3% good, AQI 47); Brazoria (84.8% good, AQI 33); Brazos (63.4% good, AQI 43).
Air Quality Summary
Good Days
36.2%
88 of 243 monitored days
-38.8pp vs 75% target
Max AQI Recorded
140
USG
Health Grade
Poor
90th-pct AQI 74
Hidalgo County, Good days share 36.2%
National avg
Share of monitored days at AQI 0-50 (Good band).
Hidalgo 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).
AQI Day Breakdown (2025)
Distribution of 243 monitored days across EPA AQI categories.
Good
88
36%
Moderate
151
62%
USG
4
2%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Hidalgo County.
- PM2.5 · 197 days · 81.1%
- Ozone · 38 days · 15.6%
- PM10 · 8 days · 3.3%
Health Impact Assessment
Poor
Hidalgo County's air quality is rated Poor based on 36.2% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 36.2% of monitored days in 2025, with a median AQI of 54. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 197 of 243 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Hidalgo County. Best year: 2020 (222 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 222 | 139 | 3 | 2 | 44 | 157 |
| 2021 | 169 | 192 | 2 | 0 | 52 | 108 |
| 2022 | 197 | 165 | 3 | 0 | 49 | 136 |
| 2023 | 206 | 151 | 0 | 0 | 44 | 95 |
| 2024 | 150 | 192 | 19 | 5 | 54 | 157 |
| 2025 | 88 | 151 | 4 | 0 | 54 | 140 |
How does Hidalgo County compare?
How Hidalgo County compares
Good-day share worse than US avg
Hidalgo County 36.2%
Atascosa County, Texas 58.0%
US average 76.5%
Median AQI worse than US avg
Hidalgo County 54
Atascosa County, Texas 45
US average 38
Unhealthy days / yr about average
Hidalgo County 0
Atascosa County, Texas 0
US average 0
Other Counties in Texas
Air quality comparison for nearby counties in Texas.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Hidalgo County.
Denver County, Colorado
AQI 54 · 44.2% good
Franklin County, Ohio
AQI 54 · 39.8% good
Fresno County, California
AQI 54 · 40.1% good
Hamilton County, Ohio
AQI 54 · 32.1% good
Inyo County, California
AQI 54 · 40.7% good
Larimer County, Colorado
AQI 54 · 40.1% good
What Hidalgo County's air means for you
The air here stays in the breathable range year-round, with PM2.5 the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 54 means for exposure. Health guidance
- See how Hidalgo County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Hidalgo County with its Texas neighbours before drawing a conclusion about the region. All of Texas
Based on 243 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
More Air Quality Data
Air Quality Guides
Frequently Asked Questions
What is the air quality in Hidalgo County, Texas? ▼
Hidalgo County has a median Air Quality Index (AQI) of 54, rated "Moderate." 36.2% of monitored days (88 out of 243) had good air quality in 2025.
What is the main pollutant in Hidalgo County? ▼
The primary pollutant in Hidalgo County is Fine Particles (PM2.5), which was the main AQI driver on 197 days (81% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Hidalgo County have? ▼
In 2025, Hidalgo County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 140.
Is the air quality in Hidalgo County getting better or worse? ▼
Air quality in Hidalgo County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 222 good days. Worst year: 2025 with 88 good days.
What does AQI 54 mean for health? ▼
Hidalgo County's median AQI of 54 falls in the "Moderate" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Hidalgo County compare to other counties in Texas? ▼
Hidalgo County has 36.2% good air days. Nearby counties in Texas: Atascosa (58.0% good), Bell (61.3% good), Bexar (39.8% good), Bowie (57.3% good), Brazoria (84.8% good), Brazos (63.4% good).
What is the 90th percentile AQI in Hidalgo County? ▼
The 90th percentile AQI for Hidalgo County is 74, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 140 (USG).
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.
Every figure on PlainAir 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.