Metro area air quality · 2025

Guayama, PR

Median AQI 19 (Good). 98.0% of monitored days rated Good across this metro's EPA monitoring network.

19
Median AQI
98.0%
Good-air days
0
Unhealthy days

Guayama, PR posted a 2025 median AQI of 19 (Good) with 98.0% Good days

According to the U.S. EPA Air Quality System, the Guayama, PR CBSA recorded a median AQI of 19 across 50 monitored days in 2025, with 98.0% rated Good and 0 unhealthy or worse. This is an annual metro comparison, not a live advisory.

Data source EPA Air Quality System (AQS)

Closest median-AQI peer
Marquette, MI (82.4% Good, median AQI 19) is the closest nationwide median-AQI peer to Guayama, PR.
2020–2025 Good-day shift
Guayama, PR's Good-day share moved +21.5 points from 2020 to 2025 (median AQI -12).
Median AQI
Median AQI: 19
Good days
Good days: 98.0%

Aggregated from EPA Air Quality System (2025), 50 monitored days. EPA AQS →

The verdict

The Guayama, PR metro runs good on the EPA scale, a median AQI of 19 with 98.0% of 50 monitored days in the Good band.

19
median AQI · Good
98.0%
days rated Good
52
worst single reading

No day crossed into the Unhealthy tier across the metro's monitors in 2025.

Insights: Guayama, PR metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 19 over 50 measured days in 2025, which corresponds to a Good band and a Excellent metro-wide health grade. The monitored-day split lands at 49 Good days (98%), 1 Moderate (2%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 37 while the highest single-day reading hit 52 (Moderate). Metro residents averaged roughly 29.4 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, the share of monitored days rated Good shifted by +21.5 points (measured against 34 monitored days in 2020 and 50 in 2025, so raw day counts are not comparable) and the median AQI moved -12 points, which classifies the multi-year trajectory as tracked. The metro recorded no Unhealthy-tier days in this annual dataset. Metros with comparable AQI profiles include Marquette, MI (82.4% good, AQI 19); Centralia, WA (91.3% good, AQI 20); Pierre, SD (93.0% good, AQI 18).

Air Quality Summary

Median AQI

19

Good

Good Days

98.0%

49 of 50 days

Max AQI

52

Moderate

Health Grade

Excellent

90th pct: 37

AQI Day Breakdown (2025)

Distribution of 50 monitored days across EPA AQI categories.

Good

49

98%

Moderate

1

2%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Excellent

The Guayama, PR metro area's air quality is rated Excellent based on 98.0% good air days. No unhealthy air days were recorded in 2025.

Air quality is generally acceptable. Unusually sensitive people should monitor real-time conditions at AirNow.gov during high-pollution events.

How does the Guayama, PR metro compare?

How Guayama, PR compares

Good-day share better than typical
Guayama, PR 98.0%
Marquette, MI 82.4%
Typical US metro 70.6%
Median AQI better than typical
Guayama, PR 19
Marquette, MI 19
Typical US metro 41
Unhealthy days / yr better than typical
Guayama, PR 0
Marquette, MI 6
Typical US metro 1

5-Year Air Quality Trend

Air quality is being tracked in the Guayama, PR metro.

Year Good Moderate Unhealthy Median AQI
2020 26 8 0 31
2021 39 15 0 28
2022 65 2 0 16
2023 57 2 0 15
2024 51 1 0 15
2025 49 1 0 19

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Guayama, PR (19).

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Guayama, PR's 0 (independent of median AQI).

More Air Quality Data

Explore EPA air quality rankings and guides across U.S. metros and counties.

Air Quality Guides

Frequently Asked Questions

What is the air quality in the Guayama, PR metro area?
The Guayama, PR metro area has a median Air Quality Index (AQI) of 19, rated "Good." 98.0% of monitored days (49 out of 50) had good air quality in 2025.
How many unhealthy air days does Guayama, PR have?
In 2025, the Guayama, PR metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 52.
Is air quality in Guayama, PR getting better or worse?
Insufficient floor-qualifying trend data is available for the Guayama, PR metro area (need ≥100 monitored days in at least two years).
What does AQI 19 mean for health?
An AQI of 19 is "Good", air quality is satisfactory and poses little or no health risk. This is the best category on the EPA's AQI scale.
What is the 90th percentile AQI for Guayama, PR?
The 90th percentile AQI for the Guayama, PR metro area is 37, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 52 (Moderate).
How does Guayama, PR compare to other metro areas?
The Guayama, PR metro has 98.0% good air days. Similar metros: Marquette, MI (82.4% good), Centralia, WA (91.3% good), Pierre, SD (93.0% good).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2025. See our methodology for how AQI, median, and coverage figures are computed.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary files (metro-level) · 2020–2025

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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.