EnviroNearby

Rio Grande, Puerto Rico air quality history

Daily Air Quality Index summaries from EPA monitors in Rio Grande, Puerto Rico, 1995–2008.

98%
Good days in 2008
15
Median daily AQI, 2008
0
Days above 100 in 2008
45
Days with an AQI in 2008 (of 366)

In 2008, EPA reported a daily Air Quality Index (AQI) for Rio Grande, Puerto Rico on 45 days. 44 of those days (98%) were in the Good range, and the median daily AQI was 15. That median is lower than the typical monitored county in Puerto Rico (median 22 across 6 counties), and lower than the typical monitored U.S. county (44). The main pollutant was coarse particles (PM10) on 45 days.

EPA did not report an AQI for every day of 2008 here (45 of 366 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.

The most recent year with data for this county is 2008; EPA's files for 2009–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (2003, 2004, 2005, 2006, 2007, 2008…) 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%1995: Good 58 of 58 days19951996: Good 56 of 57 days1996: Moderate 1 of 57 days19961997: Good 49 of 53 days1997: Moderate 4 of 53 days19971998: Good 42 of 43 days1998: Moderate 1 of 43 days19981999: Good 44 of 44 days19992000: Good 44 of 47 days2000: Moderate 3 of 47 days20002001: Good 56 of 57 days2001: Moderate 1 of 57 days20012002: Good 56 of 58 days2002: Moderate 2 of 58 days20022003: Good 51 of 55 days2003: Moderate 4 of 55 days20032004: Good 49 of 53 days2004: Moderate 4 of 53 days20042005: Good 45 of 48 days2005: Moderate 3 of 48 days20052006: Good 48 of 49 days2006: Moderate 1 of 49 days20062007: Good 47 of 49 days2007: Moderate 2 of 49 days20072008: Good 44 of 45 days2008: Moderate 1 of 45 days2008
  • 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 year0501001995: 90th percentile AQI 251996: 90th percentile AQI 281997: 90th percentile AQI 361998: 90th percentile AQI 411999: 90th percentile AQI 322000: 90th percentile AQI 442001: 90th percentile AQI 362002: 90th percentile AQI 312003: 90th percentile AQI 372004: 90th percentile AQI 262005: 90th percentile AQI 382006: 90th percentile AQI 312007: 90th percentile AQI 342008: 90th percentile AQI 321995: Median AQI 131996: Median AQI 151997: Median AQI 181998: Median AQI 151999: Median AQI 172000: Median AQI 162001: Median AQI 162002: Median AQI 192003: Median AQI 172004: Median AQI 132005: Median AQI 142006: Median AQI 142007: Median AQI 162008: Median AQI 1519951996199719981999200020012002200320042005200620072008
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2008

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
Coarse particles (PM10)45100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2008454410000153254PM10
2007494720000163472PM10
2006494810000143151PM10
2005484530000143856PM10
2004534940000132657PM10
2003555140000173762PM10
2002585620000193155PM10
2001575610000163651PM10
2000474430000164471PM10
1999444400000173249PM10
1998434210000154176PM10
1997534940000183681PM10
1996575610000152885PM10
1995585800000132541PM10

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 1995–2008 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem