Median AQI
29
Good
Puerto Rico · County air quality · 2025
Fajardo County, Puerto Rico
Median AQI 29 (Good). 85.7% of monitored days rated Good, direct from EPA Air Quality System stations.
- 29
- Median AQI
- 85.7%
- Good-air days
- 0
- Unhealthy days
- 67%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Fajardo County's air is good on balance, cleaner than the median US county, a median AQI of 29 with 85.7% of 56 monitored days in the Good band, driven mainly by PM2.5.
- 29
- median AQI · Good
- 85.7%
- days rated Good
- PM2.5
- main pollutant
- 67%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 65.
Data updated July 2026
- Good · 48 d · 85.7%
- Moderate · 8 d · 14.3%
How did Fajardo County's air break down in 2025?
Across 56 monitored days, 48 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 65 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 56 days monitored. Median AQI: 29 (Good).
Insights: Fajardo County, Puerto Rico. EPA monitors recorded a median Air Quality Index of 29 across 56 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 48 (86%) fell in the Good band (AQI 0–50), 8 (14%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 59, while the worst single-day peak hit 65 (Moderate). Residents averaged about 25.7 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (56 days). Across the 2020–2025 trend window, good days shifted by +4 and the median AQI moved +2 points, placing the multi-year trajectory at stable. The worst single reading over the 2020–2025 window was AQI 65, moderate but never Unhealthy. Nearby counties show comparable readings: Bayamon (88.5% good, AQI 29); Caguas (94.3% good, AQI 3); Catano (64.6% good, AQI 44); Guayama (100.0% good, AQI 18); Guaynabo (86.0% good, AQI 30); Mayagnez (96.9% good, AQI 12).
Air Quality Summary
Good Days
85.7%
48 of 56 monitored days
10.7pp vs 75% target
Max AQI Recorded
65
Moderate
Health Grade
Good
90th-pct AQI 59
Fajardo County, Good days share 85.7%
National avg
Share of monitored days at AQI 0-50 (Good band).
Fajardo 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 56 monitored days across EPA AQI categories.
Good
48
86%
Moderate
8
14%
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 Fajardo County.
- PM2.5 · 56 days · 100.0%
Health Impact Assessment
Good
Fajardo County's air quality is rated Good based on 85.7% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 85.7% of monitored days in 2025, with a median AQI of 29. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 56 of 56 monitored days.
5-Year Air Quality Trend
Air quality is stable in Fajardo County. Best year: 2024 (88 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 44 | 8 | 0 | 0 | 27 | 82 |
| 2021 | 88 | 26 | 0 | 0 | 29 | 82 |
| 2022 | 73 | 11 | 0 | 0 | 25 | 78 |
| 2023 | 88 | 20 | 0 | 0 | 30 | 72 |
| 2024 | 88 | 18 | 0 | 0 | 28 | 84 |
| 2025 | 48 | 8 | 0 | 0 | 29 | 65 |
How does Fajardo County compare?
How Fajardo County compares
Good-day share better than US avg
Fajardo County 85.7%
Bayamon County, Puerto Rico 88.5%
US average 76.5%
Median AQI better than US avg
Fajardo County 29
Bayamon County, Puerto Rico 29
US average 38
Unhealthy days / yr about average
Fajardo 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 Fajardo County.
Bayamon County, Puerto Rico
AQI 29 · 88.5% good
Grant County, Oklahoma
AQI 29 · 90.0% good
Jackson County, Wisconsin
AQI 29 · 76.0% good
Nez Perce County, Idaho
AQI 29 · 84.0% good
Roane County, Tennessee
AQI 29 · 84.1% good
Washington County, Nebraska
AQI 29 · 84.3% good
What Fajardo 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 29 means for exposure. Health guidance
- See how Fajardo County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Fajardo County with its Puerto Rico neighbours before drawing a conclusion about the region. All of Puerto Rico
Based on 56 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 Fajardo County, Puerto Rico? ▼
Fajardo County has a median Air Quality Index (AQI) of 29, rated "Good." 85.7% of monitored days (48 out of 56) had good air quality in 2025.
What is the main pollutant in Fajardo County? ▼
The primary pollutant in Fajardo County is Fine Particles (PM2.5), which was the main AQI driver on 56 days (100% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Fajardo County have? ▼
In 2025, Fajardo County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 65.
Is the air quality in Fajardo County getting better or worse? ▼
Air quality in Fajardo County is stable based on 5-year trends (2020-2025). Best year: 2024 with 88 good days. Worst year: 2020 with 44 good days.
What does AQI 29 mean for health? ▼
Fajardo County's median AQI of 29 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 Fajardo County compare to other counties in Puerto Rico? ▼
Fajardo County has 85.7% good air days. Nearby counties in Puerto Rico: Bayamon (88.5% good), Caguas (94.3% good), Catano (64.6% good), Guayama (100.0% good), Guaynabo (86.0% good), Mayagnez (96.9% good).
What is the 90th percentile AQI in Fajardo County? ▼
The 90th percentile AQI for Fajardo County is 59, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 65 (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.