EnviroNearby

Madison County, New York air quality history

Daily Air Quality Index summaries from EPA monitors in Madison, New York, 1990–2012.

95%
Good days in 2011
35
Median daily AQI, 2011
0
Days above 100 in 2011
355
Days with an AQI in 2011 (of 365)

In 2011, EPA reported a daily Air Quality Index (AQI) for Madison, New York on 355 days. 339 of those days (95%) were in the Good range, and the median daily AQI was 35. That median is lower than the typical monitored county in New York (median 38.5 across 34 counties), and lower than the typical monitored U.S. county (44). The main pollutant was ozone on 355 days. Across the years with fuller monitoring, the share of Good days rose: an average of 81% in 1991–1993 versus 93% in 2009–2011.

The most recent year with data for this county is 2012; EPA's files for 2013–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (1990, 2012) 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%1990: Good 85 of 89 days1990: Moderate 4 of 89 days19901991: Good 258 of 347 days1991: Moderate 59 of 347 days1991: Unhealthy for Sensitive Groups 20 of 347 days1991: Unhealthy 10 of 347 days1992: Good 304 of 353 days1992: Moderate 39 of 353 days1992: Unhealthy for Sensitive Groups 8 of 353 days1992: Unhealthy 2 of 353 days19921993: Good 300 of 362 days1993: Moderate 47 of 362 days1993: Unhealthy for Sensitive Groups 11 of 362 days1993: Unhealthy 4 of 362 days1994: Good 302 of 359 days1994: Moderate 48 of 359 days1994: Unhealthy for Sensitive Groups 9 of 359 days19941995: Good 308 of 355 days1995: Moderate 34 of 355 days1995: Unhealthy for Sensitive Groups 12 of 355 days1995: Unhealthy 1 of 355 days1996: Good 299 of 344 days1996: Moderate 40 of 344 days1996: Unhealthy for Sensitive Groups 5 of 344 days19961997: Good 311 of 354 days1997: Moderate 35 of 354 days1997: Unhealthy for Sensitive Groups 8 of 354 days1998: Good 281 of 347 days1998: Moderate 55 of 347 days1998: Unhealthy for Sensitive Groups 10 of 347 days1998: Unhealthy 1 of 347 days19981999: Good 279 of 351 days1999: Moderate 60 of 351 days1999: Unhealthy for Sensitive Groups 11 of 351 days1999: Unhealthy 1 of 351 days2000: Good 310 of 346 days2000: Moderate 31 of 346 days2000: Unhealthy for Sensitive Groups 4 of 346 days2000: Unhealthy 1 of 346 days20002001: Good 279 of 350 days2001: Moderate 54 of 350 days2001: Unhealthy for Sensitive Groups 15 of 350 days2001: Unhealthy 2 of 350 days2002: Good 272 of 340 days2002: Moderate 47 of 340 days2002: Unhealthy for Sensitive Groups 18 of 340 days2002: Unhealthy 3 of 340 days20022003: Good 291 of 347 days2003: Moderate 49 of 347 days2003: Unhealthy for Sensitive Groups 5 of 347 days2003: Unhealthy 2 of 347 days2004: Good 316 of 347 days2004: Moderate 28 of 347 days2004: Unhealthy for Sensitive Groups 3 of 347 days20042005: Good 280 of 334 days2005: Moderate 45 of 334 days2005: Unhealthy for Sensitive Groups 9 of 334 days2006: Good 316 of 349 days2006: Moderate 32 of 349 days2006: Unhealthy for Sensitive Groups 1 of 349 days20062007: Good 308 of 358 days2007: Moderate 41 of 358 days2007: Unhealthy for Sensitive Groups 9 of 358 days2008: Good 324 of 361 days2008: Moderate 33 of 361 days2008: Unhealthy for Sensitive Groups 3 of 361 days2008: Unhealthy 1 of 361 days20082009: Good 339 of 360 days2009: Moderate 21 of 360 days2010: Good 319 of 362 days2010: Moderate 39 of 362 days2010: Unhealthy for Sensitive Groups 4 of 362 days20102011: Good 339 of 355 days2011: Moderate 16 of 355 days2012: Good 90 of 90 days2012
  • 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 year0501001990: 90th percentile AQI 441991: 90th percentile AQI 971992: 90th percentile AQI 581993: 90th percentile AQI 671994: 90th percentile AQI 641995: 90th percentile AQI 581996: 90th percentile AQI 581997: 90th percentile AQI 581998: 90th percentile AQI 741999: 90th percentile AQI 742000: 90th percentile AQI 512001: 90th percentile AQI 772002: 90th percentile AQI 772003: 90th percentile AQI 582004: 90th percentile AQI 492005: 90th percentile AQI 612006: 90th percentile AQI 502007: 90th percentile AQI 612008: 90th percentile AQI 512009: 90th percentile AQI 482010: 90th percentile AQI 542011: 90th percentile AQI 472012: 90th percentile AQI 441990: Median AQI 311991: Median AQI 391992: Median AQI 341993: Median AQI 361994: Median AQI 361995: Median AQI 361996: Median AQI 361997: Median AQI 361998: Median AQI 351999: Median AQI 392000: Median AQI 352001: Median AQI 392002: Median AQI 372003: Median AQI 372004: Median AQI 332005: Median AQI 382006: Median AQI 352007: Median AQI 372008: Median AQI 342009: Median AQI 342010: Median AQI 362011: Median AQI 352012: Median AQI 33199019921994199619982000200220042006200820102012
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2011

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
Ozone355100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2012909000000334447Ozone
20113553391600003547100Ozone
20103623193940003654140Ozone
2009360339210000344897Ozone
20083613243331003451161Ozone
20073583084190003761136Ozone
20063493163210003550133Ozone
20053342804590003861122Ozone
20043473162830003349115Ozone
20033472914952003758197Ozone
200234027247183003777172Ozone
200135027954152003977161Ozone
20003463103141003551166Ozone
199935127960111003974151Ozone
199834728155101003574164Ozone
19973543113580003658140Ozone
19963442994050003658140Ozone
199535530834121003658159Ozone
19943593024890003664136Ozone
199336230047114003667174Ozone
19923533043982003458166Ozone
1991347258592010003997192Ozone
1990898540000314497Ozone

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.

Counties in New York with a similar median AQI in 2011

All monitored counties in New York

Source: U.S. EPA AirData, “Annual AQI by County” files for 1990–2012 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem