Median AQI
44
Good
Puerto Rico · County air quality · 2025
Catano County, Puerto Rico
Median AQI 44 (Good). 64.6% of monitored days rated Good, direct from EPA Air Quality System stations.
- 44
- Median AQI
- 64.6%
- Good-air days
- 0
- Unhealthy days
- 22%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Catano County's air is good on balance, among the more polluted 10% of US counties, a median AQI of 44 with 64.6% of 175 monitored days in the Good band, driven mainly by PM2.5.
- 44
- median AQI · Good
- 64.6%
- days rated Good
- PM2.5
- main pollutant
- 22%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 93.
Data updated July 2026
- Good · 113 d · 64.6%
- Moderate · 62 d · 35.4%
How did Catano County's air break down in 2025?
Across 175 monitored days, 113 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 93 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 175 days monitored. Median AQI: 44 (Good).
Insights: Catano County, Puerto Rico. EPA monitors recorded a median Air Quality Index of 44 across 175 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 113 (65%) fell in the Good band (AQI 0–50), 62 (35%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 60, while the worst single-day peak hit 93 (Moderate). Residents averaged about 19.4 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (158 days), PM10 (17 days). Across the 2020–2025 trend window, good days shifted by -94 and the median AQI moved +16 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 93, moderate but never Unhealthy. Nearby counties show comparable readings: Bayamon (88.5% good, AQI 29); Caguas (94.3% good, AQI 3); Fajardo (85.7% good, AQI 29); Guayama (100.0% good, AQI 18); Guaynabo (86.0% good, AQI 30); Mayagnez (96.9% good, AQI 12).
Air Quality Summary
Good Days
64.6%
113 of 175 monitored days
-10.4pp vs 75% target
Max AQI Recorded
93
Moderate
Health Grade
Moderate
90th-pct AQI 60
Catano County, Good days share 64.6%
National avg
Share of monitored days at AQI 0-50 (Good band).
Catano 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 175 monitored days across EPA AQI categories.
Good
113
65%
Moderate
62
35%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Catano County.
- PM2.5 · 158 days · 90.3%
- PM10 · 17 days · 9.7%
Health Impact Assessment
Moderate
Catano County's air quality is rated Moderate based on 64.6% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 64.6% of monitored days in 2025, with a median AQI of 44. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 158 of 175 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Catano County. Best year: 2022 (228 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 207 | 52 | 5 | 6 | 28 | 332 |
| 2021 | 151 | 136 | 12 | 1 | 50 | 151 |
| 2022 | 228 | 81 | 0 | 0 | 35 | 86 |
| 2023 | 96 | 101 | 10 | 2 | 52 | 155 |
| 2024 | 168 | 130 | 30 | 11 | 51 | 162 |
| 2025 | 113 | 62 | 0 | 0 | 44 | 93 |
How does Catano County compare?
How Catano County compares
Good-day share worse than US avg
Catano County 64.6%
Bayamon County, Puerto Rico 88.5%
US average 76.5%
Median AQI worse than US avg
Catano County 44
Bayamon County, Puerto Rico 29
US average 38
Unhealthy days / yr about average
Catano County 0
Bayamon County, Puerto Rico 0
US average 0
Other Counties in Puerto Rico
Air quality comparison for nearby counties in Puerto Rico.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Catano County.
Baltimore County, Maryland
AQI 44 · 70.4% good
Baltimore (City) County, Maryland
AQI 44 · 68.7% good
Bartholomew County, Indiana
AQI 44 · 69.2% good
Berks County, Pennsylvania
AQI 44 · 65.6% good
Bolivar County, Mississippi
AQI 44 · 70.3% good
Brewster County, Texas
AQI 44 · 69.0% good
What Catano 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 44 means for exposure. Health guidance
- See how Catano County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Catano County with its Puerto Rico neighbours before drawing a conclusion about the region. All of Puerto Rico
Based on 175 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 Catano County, Puerto Rico? ▼
Catano County has a median Air Quality Index (AQI) of 44, rated "Good." 64.6% of monitored days (113 out of 175) had good air quality in 2025.
What is the main pollutant in Catano County? ▼
The primary pollutant in Catano County is Fine Particles (PM2.5), which was the main AQI driver on 158 days (90% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Catano County have? ▼
In 2025, Catano County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 93.
Is the air quality in Catano County getting better or worse? ▼
Air quality in Catano County is worsening based on 5-year trends (2020-2025). Best year: 2022 with 228 good days. Worst year: 2023 with 96 good days.
What does AQI 44 mean for health? ▼
Catano County's median AQI of 44 falls in the "Good" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Catano County compare to other counties in Puerto Rico? ▼
Catano County has 64.6% good air days. Nearby counties in Puerto Rico: Bayamon (88.5% good), Caguas (94.3% good), Fajardo (85.7% good), Guayama (100.0% good), Guaynabo (86.0% good), Mayagnez (96.9% good).
What is the 90th percentile AQI in Catano County? ▼
The 90th percentile AQI for Catano County is 60, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 93 (Moderate).
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.