EnviroNearby

Guayama, Puerto Rico air quality history

Daily Air Quality Index summaries from EPA monitors in Guayama, Puerto Rico, 1987–2025.

95%
Good days in 2013
21
Median daily AQI, 2013
0
Days above 100 in 2013
123
Days with an AQI in 2013 (of 365)

In 2013, EPA reported a daily Air Quality Index (AQI) for Guayama, Puerto Rico on 123 days. 117 of those days (95%) were in the Good range, and the median daily AQI was 21. That median is about the same as the typical monitored county in Puerto Rico (median 19 across 8 counties), and lower than the typical monitored U.S. county (42). The main pollutant was fine particles (PM2.5) on 77 days.

EPA did not report an AQI for every day of 2013 here (123 of 365 days). Figures describe monitored days only; seasonal monitoring (for example, ozone measured only in warmer months) can make a county look cleaner or dirtier than a full-year record would.

Years with fewer than 120 monitored days (2020, 2021, 2022, 2023, 2024, 2025…) are shown in the table but left out of comparisons and trend statements.

How the days broke down each year

Each bar is one year. The colored segments show the share of monitored days that fell in each AQI category.

Share of monitored days in each AQI category, by year0%25%50%75%100%1987: Good 32 of 37 days1987: Moderate 4 of 37 days1987: Unhealthy for Sensitive Groups 1 of 37 days19871988: Good 41 of 46 days1988: Moderate 5 of 46 days1989: Good 42 of 46 days1989: Moderate 4 of 46 days1990: Good 41 of 48 days1990: Moderate 7 of 48 days1991: Good 45 of 48 days1991: Moderate 3 of 48 days1992: Good 58 of 61 days1992: Moderate 3 of 61 days19921993: Good 56 of 61 days1993: Moderate 5 of 61 days1994: Good 61 of 65 days1994: Moderate 3 of 65 days1994: Unhealthy for Sensitive Groups 1 of 65 days1995: Good 106 of 111 days1995: Moderate 5 of 111 days1996: Good 106 of 110 days1996: Moderate 4 of 110 days1997: Good 98 of 108 days1997: Moderate 10 of 108 days19971998: Good 93 of 101 days1998: Moderate 8 of 101 days1999: Good 83 of 113 days1999: Moderate 30 of 113 days2000: Good 101 of 117 days2000: Moderate 16 of 117 days2001: Good 94 of 120 days2001: Moderate 26 of 120 days2002: Good 101 of 118 days2002: Moderate 17 of 118 days20022003: Good 101 of 118 days2003: Moderate 17 of 118 days2004: Good 106 of 119 days2004: Moderate 13 of 119 days2005: Good 99 of 119 days2005: Moderate 20 of 119 days2006: Good 102 of 122 days2006: Moderate 20 of 122 days2007: Good 103 of 120 days2007: Moderate 17 of 120 days20072008: Good 105 of 112 days2008: Moderate 7 of 112 days2009: Good 94 of 103 days2009: Moderate 9 of 103 days2010: Good 105 of 117 days2010: Moderate 12 of 117 days2011: Good 102 of 112 days2011: Moderate 10 of 112 days2012: Good 103 of 122 days2012: Moderate 19 of 122 days20122013: Good 117 of 123 days2013: Moderate 6 of 123 days2014: Good 98 of 106 days2014: Moderate 8 of 106 days2015: Good 91 of 110 days2015: Moderate 19 of 110 days2016: Good 85 of 102 days2016: Moderate 17 of 102 days2017: Good 36 of 44 days2017: Moderate 8 of 44 days20172019: Good 2 of 2 days2020: Good 26 of 34 days2020: Moderate 8 of 34 days2021: Good 39 of 54 days2021: Moderate 15 of 54 days2022: Good 65 of 67 days2022: Moderate 2 of 67 days2023: Good 57 of 59 days2023: Moderate 2 of 59 days20232024: Good 51 of 52 days2024: Moderate 1 of 52 days2025: Good 49 of 50 days2025: Moderate 1 of 50 days2025
  • Good
  • Moderate
  • Unhealthy for Sensitive Groups
  • Unhealthy
  • Very Unhealthy
  • Hazardous

Typical and high-end AQI over time

The median is the middle day of the year. The 90th percentile is the level that only the highest 10% of days exceeded.

Median and 90th-percentile daily AQI, by year0501001987: 90th percentile AQI 511988: 90th percentile AQI 531989: 90th percentile AQI 441990: 90th percentile AQI 541991: 90th percentile AQI 431992: 90th percentile AQI 371993: 90th percentile AQI 471994: 90th percentile AQI 471995: 90th percentile AQI 401996: 90th percentile AQI 411997: 90th percentile AQI 481998: 90th percentile AQI 481999: 90th percentile AQI 592000: 90th percentile AQI 552001: 90th percentile AQI 572002: 90th percentile AQI 532003: 90th percentile AQI 522004: 90th percentile AQI 522005: 90th percentile AQI 562006: 90th percentile AQI 552007: 90th percentile AQI 542008: 90th percentile AQI 482009: 90th percentile AQI 482010: 90th percentile AQI 512011: 90th percentile AQI 492012: 90th percentile AQI 542013: 90th percentile AQI 432014: 90th percentile AQI 422015: 90th percentile AQI 552016: 90th percentile AQI 582017: 90th percentile AQI 632019: 90th percentile AQI 292020: 90th percentile AQI 632021: 90th percentile AQI 652022: 90th percentile AQI 312023: 90th percentile AQI 372024: 90th percentile AQI 292025: 90th percentile AQI 371987: Median AQI 221988: Median AQI 291989: Median AQI 201990: Median AQI 231991: Median AQI 201992: Median AQI 191993: Median AQI 271994: Median AQI 291995: Median AQI 191996: Median AQI 191997: Median AQI 241998: Median AQI 201999: Median AQI 322000: Median AQI 322001: Median AQI 332002: Median AQI 292003: Median AQI 272004: Median AQI 262005: Median AQI 292006: Median AQI 312007: Median AQI 322008: Median AQI 242009: Median AQI 222010: Median AQI 182011: Median AQI 232012: Median AQI 222013: Median AQI 212014: Median AQI 192015: Median AQI 252016: Median AQI 282017: Median AQI 372019: Median AQI 292020: Median AQI 312021: Median AQI 282022: Median AQI 162023: Median AQI 152024: Median AQI 152025: Median AQI 19198719921997200220072012201720232025
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2013

On each monitored day, the AQI reflects whichever measured pollutant had the highest index. This counts how many days each pollutant set the AQI. A pollutant that was not measured here cannot appear.

PollutantDays as main pollutantShare of monitored days
Fine particles (PM2.5)7763%
Coarse particles (PM10)4637%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025504910000193752PM10
2024525110000152953PM10
2023595720000153755PM10
2022676520000163167PM10
20215439150000286577PM2.5
2020342680000316382PM2.5
20192200000292929PM10
2017443680000376385PM2.5
201610285170000285873PM2.5
201511091190000255568PM2.5
20141069880000194259PM10
201312311760000214357PM2.5
2012122103190000225470PM2.5
2011112102100000234961PM2.5
2010117105120000185186PM10
20091039490000224880PM2.5
200811210570000244892PM2.5
2007120103170000325480PM2.5
2006122102200000315584PM2.5
200511999200000295676PM2.5
2004119106130000265263PM2.5
2003118101170000275284PM2.5
2002118101170000295369PM2.5
200112094260000335780PM2.5
2000117101160000325580PM2.5
199911383300000325992PM2.5
19981019380000204880PM10
199710898100000244893PM10
199611010640000194161PM10
199511110650000194077PM10
19946561310002947104PM10
1993615650000274766PM10
1992615830000193770PM10
1991484530000204373PM10
1990484170000235457PM10
1989464240000204466PM10
1988464150000295391PM10
19873732410002251128PM10

What this data can and can’t tell you

It is a county-level summary. EPA reports one AQI per day for the county, based on the monitors operating there. Air at a particular street, school or home can differ, especially near roads, industry or wildfire smoke.

It is not a health assessment. The AQI is EPA’s scale for communicating daily air quality. A county’s history can’t tell you what the health risk is for any particular person. For daily conditions and health guidance, see AirNow.

Rules change over time. EPA has revised AQI breakpoints, most recently for fine particles in 2024, so some year-to-year change can reflect the scale rather than the air.

All monitored counties in Puerto Rico

Source: U.S. EPA AirData, “Annual AQI by County” files for 1987–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem