Puerto Rico · County air quality · 2025
Caguas County, Puerto Rico
Median AQI 5 (Good). 93.0% of monitored days rated Good, direct from EPA Air Quality System stations.
- 5
- Median AQI
- 93.0%
- Good-air days
- 0
- Unhealthy days
- 87%
- Cleaner than US counties
Caguas County's 2025 annual median AQI is 5 (Good), with 93.0% Good days
According to the U.S. EPA Air Quality System, Caguas County, Puerto Rico posted a 2025 median AQI of 5 (Good) across 243 monitored days, with 93.0% 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
- Caguas County's 93.0% Good-day share places it cleaner than 87% of US counties in 2025.
- Closest median-AQI peer
- Karnes County (100.0% Good, median AQI 6) is the closest nationwide median-AQI peer to Caguas County.
- 2020–2025 trend
- Caguas County's floor-qualifying Good-day share is worsening from 2020 to 2025 (96.2% → 93.0%).
- Median AQI
- Median AQI: 5
According to the 2025 EPA AQS county release on PlainAirData, Caguas County, Puerto Rico ranks #2 of 951 by median AQI (5) and #125 by good-day share (93.0%). 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
- Caguas County's peak single-day AQI fell from 174 to 71 between the 2024 and 2025 EPA annual releases, a change of -103 points.
- Caguas County's Good-day share fell from 96.1% to 93.0% between the 2024 and 2025 EPA annual releases, a change of -3.1 percentage points.
- Caguas County's Unhealthy-category days fell from 1 to 0 between the 2024 and 2025 EPA annual releases, a change of -1 days.
Data updated August 2026
- Good · 226 d · 93.0%
- Moderate · 17 d · 7.0%
How did Caguas County's air break down in 2025?
Across 243 monitored days, 226 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 71 (Moderate).
EPA AQS →Share of monitored days at AQI 0-50 (Good band).
Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).
Where Caguas County sits nationally
COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Caguas County's Good-day share is 93.0% - cleaner than 87% of that comparison set.
Caguas County Good-day share vs. every US county
Share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release
93.0% Cleaner than 87% higher than 87% of 951 US counties
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 Caguas County.
- CO · 129 days · 53.1%
- PM2.5 · 114 days · 46.9%
2024 daily-monitor rhythm in Caguas County
Month-by-month median AQI from EPA day-level county monitors (357 reported days in 2024). Jun posted the highest typical readings (median AQI 10, peak 63); Nov was cleanest at median 3. Summer months (Jun–Aug) averaged median AQI 6 vs 4 in Dec–Feb. 1 day crossed Unhealthy (AQI >150) at least once that year.
Five-year seasonal record
EPA day-level county files · 2020–20241,435 daily readings show a recurring local pattern: Aug has the highest matched-month median AQI (16), while Nov is lowest (7). Each cell is that month’s median daily AQI, not a current-air forecast.
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
Caguas County's air quality is rated Excellent based on 93.0% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 93.0% of monitored days in 2025, with a median AQI of 5. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is CO, driving AQI on 129 of 243 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Caguas County. Highest Good-day share: 2020 (96.2%, 306 of 318 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 306 | 12 | 0 | 0 | 10 | 72 |
| 2021 | 180 | 17 | 0 | 0 | 14 | 75 |
| 2022 | 291 | 16 | 0 | 0 | 9 | 76 |
| 2023 | 242 | 13 | 1 | 0 | 6 | 105 |
| 2024 | 343 | 13 | 0 | 1 | 3 | 174 |
| 2025 | 226 | 17 | 0 | 0 | 5 | 71 |
How does Caguas County compare?
How Caguas County compares
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 Caguas County, Puerto Rico · 2020–2025
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.