Puerto Rico · County air quality · 2025
Ponce County, Puerto Rico
Median AQI 3 (Good). 91.4% of monitored days rated Good, direct from EPA Air Quality System stations.
- 3
- Median AQI
- 91.4%
- Good-air days
- 0
- Unhealthy days
- 83%
- Cleaner than US counties
Ponce County's 2025 annual median AQI is 3 (Good), with 91.4% Good days
According to the U.S. EPA Air Quality System, Ponce County, Puerto Rico posted a 2025 median AQI of 3 (Good) across 257 monitored days, with 91.4% 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
- Ponce County's 91.4% Good-day share places it cleaner than 83% of US counties in 2025.
- Closest median-AQI peer
- Caguas County (93.0% Good, median AQI 5) is the closest nationwide median-AQI peer to Ponce County.
- 2020–2025 trend
- Ponce County's floor-qualifying Good-day share is improving from 2020 to 2025 (88.6% → 91.4%).
- Median AQI
- Median AQI: 3
According to the 2025 EPA AQS county release on PlainAirData, Ponce County, Puerto Rico is #1 of 951 by median AQI (3, 91.4% Good days) at good-day-share #159 ≠ Kenai Peninsula County, Alaska #1 lowest good-day share (100.0%, median AQI 9).
Annual release change
What changed in the 2025 EPA annual release
- Ponce County's Good-day share fell from 94.3% to 91.4% between the 2024 and 2025 EPA annual releases, a change of -2.9 percentage points.
Data updated August 2026
- Good · 235 d · 91.4%
- Moderate · 22 d · 8.6%
How did Ponce County's air break down in 2025?
Across 257 monitored days, 235 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 74 (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 Ponce County sits nationally
COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Ponce County's Good-day share is 91.4% - cleaner than 83% of that comparison set.
Ponce County Good-day share vs. every US county
Share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release
91.4% Cleaner than 83% higher than 83% 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 Ponce County.
- CO · 140 days · 54.5%
- PM2.5 · 111 days · 43.2%
- PM10 · 6 days · 2.3%
2024 daily-monitor rhythm in Ponce County
Month-by-month median AQI from EPA day-level county monitors (336 reported days in 2024). Oct posted the highest typical readings (median AQI 19, peak 60); Sep was cleanest at median 3. Summer months (Jun–Aug) averaged median AQI 3 vs 4 in Dec–Feb.
Five-year seasonal record
EPA day-level county files · 2020–20241,548 daily readings show a recurring local pattern: Sep has the highest matched-month median AQI (27), while Nov is lowest (9). 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
Ponce County's air quality is rated Excellent based on 91.4% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 91.4% of monitored days in 2025, with a median AQI of 3. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is CO, driving AQI on 140 of 257 monitored days.
5-Year Air Quality Trend
Air quality is improving in Ponce County. Highest Good-day share: 2024 (94.3%, 317 of 336 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 319 | 41 | 0 | 0 | 23 | 81 |
| 2021 | 176 | 37 | 0 | 1 | 30 | 380 |
| 2022 | 264 | 31 | 0 | 0 | 18 | 99 |
| 2023 | 258 | 82 | 0 | 0 | 30 | 83 |
| 2024 | 317 | 19 | 0 | 0 | 3 | 82 |
| 2025 | 235 | 22 | 0 | 0 | 3 | 74 |
How does Ponce County compare?
How Ponce 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 Ponce 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.