EnviroNearby

Monroe County, Florida air quality history

Daily Air Quality Index summaries from EPA monitors in Monroe, Florida, 1997–2001.

100%
Good days in 2001
16
Median daily AQI, 2001
0
Days above 100 in 2001
45
Days with an AQI in 2001 (of 365)

In 2001, EPA reported a daily Air Quality Index (AQI) for Monroe, Florida on 45 days. 45 of those days (100%) were in the Good range, and the median daily AQI was 16. That median is lower than the typical monitored county in Florida (median 41 across 34 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 2001 here (45 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.

The most recent year with data for this county is 2001; EPA's files for 2002–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (1997, 1998, 1999, 2000, 2001) 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%1997: Good 4 of 4 days19971998: Good 49 of 50 days1998: Moderate 1 of 50 days19981999: Good 57 of 57 days19992000: Good 60 of 61 days2000: Moderate 1 of 61 days20002001: Good 45 of 45 days2001
  • 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 year0501001997: 90th percentile AQI 201998: 90th percentile AQI 321999: 90th percentile AQI 222000: 90th percentile AQI 252001: 90th percentile AQI 281997: Median AQI 191998: Median AQI 171999: Median AQI 132000: Median AQI 162001: Median AQI 1619971998199920002001
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2001

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
2001454500000162850PM10
2000616010000162553PM10
1999575700000132249PM10
1998504910000173265PM10
19974400000192020PM10

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 Florida

Source: U.S. EPA AirData, “Annual AQI by County” files for 1997–2001 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem