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

Guayama, PR sits in the upper Good-day tercile among EPA CBSA metros on this site (98.0% of 50 monitored days). On the EPA scale the metro runs good, with a median AQI of 19 and 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.

Guayama, PR sits in the upper Good-day tercile among EPA CBSA metros on this site (98.0% of 50 monitored days). Signature read: 98.0% Good-day share (high tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 19 over 50 measured days in 2025 (Good / Excellent). The monitored-day split lands at 49 Good (98%), 1 Moderate (2%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 37; the highest single-day reading hit 52 (Moderate).

Across 2020–2025, Good-day share shifted +21.5 points and median AQI moved -12 (tracked). No Unhealthy-tier days appear 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).

Best and worst city air quality →

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).

Marquette, MI

Median AQI 19 · 82.4% Good-day share

19

Centralia, WA

Median AQI 20 · 91.3% Good-day share

20

Pierre, SD

Median AQI 18 · 93.0% Good-day share

18

Deming, NM

Median AQI 17 · 84.7% Good-day share

17

Hailey, ID

Median AQI 17 · 96.6% Good-day share

17

Kahului-Wailuku-Lahaina, HI

Median AQI 21 · 98.1% Good-day share

21

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).

Aberdeen, SD

0 unhealthy-or-worse days · median AQI 27

27

Aberdeen, WA

0 unhealthy-or-worse days · median AQI 22

22

Adrian, MI

0 unhealthy-or-worse days · median AQI 41

41

Akron, OH

0 unhealthy-or-worse days · median AQI 45

45

Albany, GA

0 unhealthy-or-worse days · median AQI 46

46

Albany, OR

0 unhealthy-or-worse days · median AQI 27

27

Frequently Asked Questions

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.
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.
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.
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).
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).

Data Sources

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

Read our methodology , how this data is sourced, computed, and verified.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary, Guayama, PR · 2020–2025