Metro area air quality · 2025
San Juan-Carolina-Caguas, PR
Median AQI 46 (Good). 59.6% of monitored days rated Good across this metro's EPA monitoring network.
- 46
- Median AQI
- 59.6%
- Good-air days
- 0
- Unhealthy days
- 25%
- Cleaner than US metros
San Juan-Carolina-Caguas, PR posted a 2025 median AQI of 46 (Good) with 59.6% Good days
According to the U.S. EPA Air Quality System, the San Juan-Carolina-Caguas, PR CBSA recorded a median AQI of 46 across 354 monitored days in 2025, with 59.6% rated Good and 0 unhealthy or worse. This is an annual metro comparison, not a live advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US metros
- The San Juan-Carolina-Caguas, PR CBSA's 59.6% Good-day share places it cleaner than 25% of US metros in 2025.
- Closest median-AQI peer
- Albany, GA (57.3% Good, median AQI 46) is the closest nationwide median-AQI peer to San Juan-Carolina-Caguas, PR.
- 2020–2025 Good-day shift
- San Juan-Carolina-Caguas, PR's Good-day share moved -21.2 points from 2020 to 2025 (median AQI +16).
- Median AQI
- Median AQI: 46
Aggregated from EPA Air Quality System (2025), 354 monitored days. EPA AQS →
The verdict
San Juan-Carolina-Caguas, PR lands in the lower Good-day tercile (59.6% Good), a thinner clean-air share than most CBSA peers here. On the EPA scale the metro runs good, more polluted than the median US metro, with a median AQI of 46 and 59.6% of 354 monitored days in the Good band.
- 46
- median AQI · Good
- 59.6%
- days rated Good
- 25%
- cleaner than US metros
- 102
- worst single reading
No day crossed into the Unhealthy tier across the metro's monitors in 2025.
Annual release change
What changed in the 2025 EPA annual release
- San Juan-Carolina-Caguas, PR metro's Unhealthy-category days fell from 12 to 0 between the 2024 and 2025 EPA annual releases, a change of -12 days.
- San Juan-Carolina-Caguas, PR metro's peak single-day AQI fell from 174 to 102 between the 2024 and 2025 EPA annual releases, a change of -72 points.
- San Juan-Carolina-Caguas, PR metro's Good-day share rose from 55.2% to 59.9% between the 2024 and 2025 EPA annual releases, a change of +4.7 percentage points.
- San Juan-Carolina-Caguas, PR metro's median AQI fell from 49 to 46 between the 2024 and 2025 EPA annual releases, a change of -3 points.
San Juan-Carolina-Caguas, PR lands in the lower Good-day tercile (59.6% Good), a thinner clean-air share than most CBSA peers here. Signature read: 59.6% Good-day share (low tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 46 over 354 measured days in 2025 (Good / Moderate). The monitored-day split lands at 211 Good (60%), 141 Moderate (40%), and 2 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 63; the highest single-day reading hit 102 (USG).
Across 2020–2025, Good-day share shifted -21.2 points and median AQI moved +16 (worsening). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Albany, GA (57.3% good, AQI 46); Athens-Clarke County, GA (57.8% good, AQI 46); Brookings, SD (58.6% good, AQI 46).
Air Quality Summary
Median AQI
46
Good
Good Days
59.6%
211 of 354 days
Max AQI
102
USG
Health Grade
Moderate
90th pct: 63
AQI Day Breakdown (2025)
Distribution of 354 monitored days across EPA AQI categories.
Good
211
60%
Moderate
141
40%
USG
2
1%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The San Juan-Carolina-Caguas, PR metro area's air quality is rated Moderate based on 59.6% 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 San Juan-Carolina-Caguas, PR metro compare?
How San Juan-Carolina-Caguas, PR compares
5-Year Air Quality Trend
Air quality is worsening in the San Juan-Carolina-Caguas, PR metro. Highest Good-day share: 2020 (81.1%, 288 of 355 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 288 | 60 | 7 | 30 | 332 |
| 2021 | 199 | 150 | 1 | 42 | 151 |
| 2022 | 276 | 85 | 0 | 34 | 86 |
| 2023 | 185 | 120 | 2 | 42 | 155 |
| 2024 | 185 | 138 | 12 | 49 | 174 |
| 2025 | 211 | 141 | 0 | 46 | 102 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near San Juan-Carolina-Caguas, PR (46).
Albany, GA
Median AQI 46 · 57.3% Good-day share
Athens-Clarke County, GA
Median AQI 46 · 57.8% Good-day share
Brookings, SD
Median AQI 46 · 58.6% Good-day share
Chico, CA
Median AQI 46 · 65.2% Good-day share
Colorado Springs, CO
Median AQI 46 · 68.2% Good-day share
Davenport-Moline-Rock Island, IA-IL
Median AQI 46 · 56.7% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to San Juan-Carolina-Caguas, PR's 0 (independent of median AQI).
Aberdeen, SD
0 unhealthy-or-worse days · median AQI 27
Aberdeen, WA
0 unhealthy-or-worse days · median AQI 22
Adrian, MI
0 unhealthy-or-worse days · median AQI 41
Akron, OH
0 unhealthy-or-worse days · median AQI 45
Albany, OR
0 unhealthy-or-worse days · median AQI 27
Albany-Schenectady-Troy, NY
0 unhealthy-or-worse days · median AQI 41
Frequently Asked Questions
How many unhealthy air days does San Juan-Carolina-Caguas, PR have? ▼
What is the air quality in the San Juan-Carolina-Caguas, PR metro area? ▼
Is air quality in San Juan-Carolina-Caguas, PR getting better or worse? ▼
What does AQI 46 mean for health? ▼
How does San Juan-Carolina-Caguas, PR compare to other metro areas? ▼
What is the 90th percentile AQI for San Juan-Carolina-Caguas, PR? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for San Juan-Carolina-Caguas, 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, San Juan-Carolina-Caguas, PR · 2020–2025