What is the air quality in Guayama County, Puerto Rico?

EPA monitors reported only 50 days for Guayama County in 2025, below the 100-day floor used for annual conclusions. Within that limited sample, the median AQI was 19 and 49 days were rated Good; this does not describe the full year.

What is the main pollutant in Guayama County?

The primary pollutant in Guayama County is Coarse Particles (PM10), which was the main AQI driver on 50 days (100% of monitored days). Irritates airways and can aggravate asthma and bronchitis.

How many unhealthy air days does Guayama County have?

Among 50 reported days in 2025, 0 reached Unhealthy or worse. Because the record is below 100 monitored days, that count cannot establish how many unhealthy days occurred across the full year.

Is the air quality in Guayama County getting better or worse?

Insufficient trend data is available for Guayama County.

What does AQI 19 mean for health?

The median of the 50 reported days was AQI 19, in the "Good" category. The limited sample is not enough to assign the county a full-year health grade. See the AQI category guide for day-level meaning and EPA AirNow for current conditions.

How does Guayama County compare to other counties in Puerto Rico?

Guayama County is not placed in county comparisons because its 50-day record is below the 100-day comparison floor.

What is the 90th percentile AQI in Guayama County?

The 90th percentile AQI for Guayama County is 37, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 52 (Moderate).

Puerto Rico · County air quality · 2025

Guayama County, Puerto Rico

Limited EPA sample: 50 monitored days, below the 100-day floor for a full-year verdict. The figures below describe only those reported days.

Compiled by PlainAirData · August 23, 2026

19
Sample median AQI: 98.0%
Good in sample: 0
Unhealthy in sample: 50
100-day comparison floor

Guayama County has only 50 EPA-monitored days in 2025, below the 100-day annual floor

According to the U.S. EPA Air Quality System, Guayama County, Puerto Rico reported 50 monitored days in 2025. That sample is too thin for a full-year air-quality grade or peer ranking. Use the figures only as the reported-day record, and check AirNow for current conditions.

Data source EPA Air Quality System (AQS)

Monitored days: Guayama County reported 50 monitored days in 2025, below the 100-day floor: sample-only, not a full-year peer rank.
Sample median AQI: Sample median AQI: 19
Annual floor: Annual floor: 100

Data updated August 2026

Good · 49 d · 98.0%
Moderate · 1 d · 2.0%

How did Guayama County's reported sample break down in 2025?

Across 50 monitored days, 49 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 52 (Moderate).

EPA AQS →

Pollutant Breakdown

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

PM10 · 50 days · 100.0%

Sample Coverage and Health Context

Limited sample

Guayama County has no annual health grade because only 50 days were reported, below the 100-day floor. The 98.0% Good-day share describes only that sample.

Reported days do not reveal what happened during unmonitored parts of the year, including seasonal smoke, ozone, or inversion periods. Use these values as a description of the available EPA sample only, and check AirNow.gov for current health guidance.

The dominant pollutant is PM10, driving AQI on 50 of 50 monitored days.

5-Year Air Quality Trend

Air quality is being tracked in Guayama County. The 2025 row is shown for transparency but excluded from the direction because it has fewer than 100 monitored days.

Year	Good	Moderate	Median AQI	Max AQI
2020	26	8	31	82
2021	39	15	28	77
2022	65	2	16	67
2023	57	2	15	55
2024	51	1	15	53
2025	49	1	19	52

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 Guayama County, Puerto Rico · 2020–2025 Accessed 2026-08-23

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.