EnviroNearby

Suffolk County, New York air quality history

Daily Air Quality Index summaries from EPA monitors in Suffolk, New York, 1980–2025.

73%
Good days in 2025
41
Median daily AQI, 2025
5
Days above 100 in 2025
365
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Suffolk, New York on 365 days. 265 of those days (73%) were in the Good range, and the median daily AQI was 41. That median is higher than the typical monitored county in New York (median 36 across 27 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 255 days. Across the years with fuller monitoring, the share of Good days fell: an average of 84% in 1980–1982 versus 76% in 2023–2025.

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%1980: Good 249 of 336 days1980: Moderate 38 of 336 days1980: Unhealthy for Sensitive Groups 21 of 336 days1980: Unhealthy 16 of 336 days1980: Very Unhealthy 12 of 336 days19801981: Good 315 of 351 days1981: Moderate 19 of 351 days1981: Unhealthy for Sensitive Groups 9 of 351 days1981: Unhealthy 7 of 351 days1981: Very Unhealthy 1 of 351 days1982: Good 256 of 294 days1982: Moderate 28 of 294 days1982: Unhealthy for Sensitive Groups 9 of 294 days1982: Unhealthy 1 of 294 days1983: Good 211 of 288 days1983: Moderate 32 of 288 days1983: Unhealthy for Sensitive Groups 19 of 288 days1983: Unhealthy 15 of 288 days1983: Very Unhealthy 11 of 288 days1984: Good 336 of 343 days1984: Moderate 7 of 343 days1985: Good 260 of 302 days1985: Moderate 29 of 302 days1985: Unhealthy for Sensitive Groups 6 of 302 days1985: Unhealthy 6 of 302 days1985: Very Unhealthy 1 of 302 days19851986: Good 295 of 355 days1986: Moderate 38 of 355 days1986: Unhealthy for Sensitive Groups 12 of 355 days1986: Unhealthy 7 of 355 days1986: Very Unhealthy 3 of 355 days1987: Good 297 of 354 days1987: Moderate 23 of 354 days1987: Unhealthy for Sensitive Groups 22 of 354 days1987: Unhealthy 4 of 354 days1987: Very Unhealthy 8 of 354 days1988: Good 288 of 344 days1988: Moderate 22 of 344 days1988: Unhealthy for Sensitive Groups 16 of 344 days1988: Unhealthy 13 of 344 days1988: Very Unhealthy 5 of 344 days1989: Good 266 of 326 days1989: Moderate 34 of 326 days1989: Unhealthy for Sensitive Groups 12 of 326 days1989: Unhealthy 10 of 326 days1989: Very Unhealthy 4 of 326 days1990: Good 281 of 346 days1990: Moderate 32 of 346 days1990: Unhealthy for Sensitive Groups 15 of 346 days1990: Unhealthy 13 of 346 days1990: Very Unhealthy 5 of 346 days19901991: Good 268 of 359 days1991: Moderate 44 of 359 days1991: Unhealthy for Sensitive Groups 22 of 359 days1991: Unhealthy 19 of 359 days1991: Very Unhealthy 6 of 359 days1992: Good 306 of 366 days1992: Moderate 38 of 366 days1992: Unhealthy for Sensitive Groups 15 of 366 days1992: Unhealthy 6 of 366 days1992: Very Unhealthy 1 of 366 days1993: Good 299 of 365 days1993: Moderate 35 of 365 days1993: Unhealthy for Sensitive Groups 14 of 365 days1993: Unhealthy 15 of 365 days1993: Very Unhealthy 2 of 365 days1994: Good 270 of 355 days1994: Moderate 46 of 355 days1994: Unhealthy for Sensitive Groups 27 of 355 days1994: Unhealthy 11 of 355 days1994: Very Unhealthy 1 of 355 days1995: Good 302 of 363 days1995: Moderate 38 of 363 days1995: Unhealthy for Sensitive Groups 14 of 363 days1995: Unhealthy 4 of 363 days1995: Very Unhealthy 5 of 363 days19951996: Good 301 of 364 days1996: Moderate 41 of 364 days1996: Unhealthy for Sensitive Groups 14 of 364 days1996: Unhealthy 8 of 364 days1997: Good 305 of 365 days1997: Moderate 33 of 365 days1997: Unhealthy for Sensitive Groups 16 of 365 days1997: Unhealthy 7 of 365 days1997: Very Unhealthy 4 of 365 days1998: Good 280 of 364 days1998: Moderate 47 of 364 days1998: Unhealthy for Sensitive Groups 26 of 364 days1998: Unhealthy 9 of 364 days1998: Very Unhealthy 2 of 364 days1999: Good 275 of 363 days1999: Moderate 55 of 363 days1999: Unhealthy for Sensitive Groups 16 of 363 days1999: Unhealthy 13 of 363 days1999: Very Unhealthy 4 of 363 days2000: Good 246 of 366 days2000: Moderate 102 of 366 days2000: Unhealthy for Sensitive Groups 13 of 366 days2000: Unhealthy 3 of 366 days2000: Very Unhealthy 2 of 366 days20002001: Good 234 of 365 days2001: Moderate 106 of 365 days2001: Unhealthy for Sensitive Groups 17 of 365 days2001: Unhealthy 6 of 365 days2001: Very Unhealthy 2 of 365 days2002: Good 244 of 365 days2002: Moderate 76 of 365 days2002: Unhealthy for Sensitive Groups 28 of 365 days2002: Unhealthy 12 of 365 days2002: Very Unhealthy 5 of 365 days2003: Good 261 of 365 days2003: Moderate 78 of 365 days2003: Unhealthy for Sensitive Groups 20 of 365 days2003: Unhealthy 3 of 365 days2003: Very Unhealthy 3 of 365 days2004: Good 269 of 366 days2004: Moderate 81 of 366 days2004: Unhealthy for Sensitive Groups 13 of 366 days2004: Unhealthy 3 of 366 days2005: Good 255 of 365 days2005: Moderate 84 of 365 days2005: Unhealthy for Sensitive Groups 17 of 365 days2005: Unhealthy 9 of 365 days20052006: Good 257 of 365 days2006: Moderate 91 of 365 days2006: Unhealthy for Sensitive Groups 12 of 365 days2006: Unhealthy 4 of 365 days2006: Very Unhealthy 1 of 365 days2007: Good 262 of 365 days2007: Moderate 79 of 365 days2007: Unhealthy for Sensitive Groups 19 of 365 days2007: Unhealthy 5 of 365 days2008: Good 253 of 366 days2008: Moderate 90 of 366 days2008: Unhealthy for Sensitive Groups 16 of 366 days2008: Unhealthy 7 of 366 days2009: Good 288 of 365 days2009: Moderate 70 of 365 days2009: Unhealthy for Sensitive Groups 6 of 365 days2009: Unhealthy 1 of 365 days2010: Good 247 of 365 days2010: Moderate 93 of 365 days2010: Unhealthy for Sensitive Groups 22 of 365 days2010: Unhealthy 3 of 365 days20102011: Good 201 of 365 days2011: Moderate 147 of 365 days2011: Unhealthy for Sensitive Groups 12 of 365 days2011: Unhealthy 4 of 365 days2011: Very Unhealthy 1 of 365 days2012: Good 233 of 365 days2012: Moderate 119 of 365 days2012: Unhealthy for Sensitive Groups 9 of 365 days2012: Unhealthy 4 of 365 days2013: Good 225 of 365 days2013: Moderate 131 of 365 days2013: Unhealthy for Sensitive Groups 7 of 365 days2013: Unhealthy 2 of 365 days2014: Good 244 of 365 days2014: Moderate 120 of 365 days2014: Unhealthy for Sensitive Groups 1 of 365 days2015: Good 241 of 365 days2015: Moderate 110 of 365 days2015: Unhealthy for Sensitive Groups 14 of 365 days20152016: Good 254 of 366 days2016: Moderate 104 of 366 days2016: Unhealthy for Sensitive Groups 8 of 366 days2017: Good 271 of 365 days2017: Moderate 85 of 365 days2017: Unhealthy for Sensitive Groups 7 of 365 days2017: Unhealthy 2 of 365 days2018: Good 254 of 365 days2018: Moderate 100 of 365 days2018: Unhealthy for Sensitive Groups 10 of 365 days2018: Unhealthy 1 of 365 days2019: Good 276 of 365 days2019: Moderate 80 of 365 days2019: Unhealthy for Sensitive Groups 9 of 365 days2020: Good 282 of 366 days2020: Moderate 78 of 366 days2020: Unhealthy for Sensitive Groups 6 of 366 days20202021: Good 281 of 365 days2021: Moderate 73 of 365 days2021: Unhealthy for Sensitive Groups 10 of 365 days2021: Unhealthy 1 of 365 days2022: Good 272 of 365 days2022: Moderate 85 of 365 days2022: Unhealthy for Sensitive Groups 8 of 365 days2023: Good 278 of 365 days2023: Moderate 74 of 365 days2023: Unhealthy for Sensitive Groups 11 of 365 days2023: Unhealthy 2 of 365 days2024: Good 291 of 366 days2024: Moderate 69 of 366 days2024: Unhealthy for Sensitive Groups 6 of 366 days2025: Good 265 of 365 days2025: Moderate 95 of 365 days2025: Unhealthy for Sensitive Groups 3 of 365 days2025: Unhealthy 2 of 365 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 year0501001501980: 90th percentile AQI 1431981: 90th percentile AQI 511982: 90th percentile AQI 581983: 90th percentile AQI 1501984: 90th percentile AQI 361985: 90th percentile AQI 741986: 90th percentile AQI 741987: 90th percentile AQI 971988: 90th percentile AQI 931989: 90th percentile AQI 871990: 90th percentile AQI 931991: 90th percentile AQI 1081992: 90th percentile AQI 801993: 90th percentile AQI 901994: 90th percentile AQI 1011995: 90th percentile AQI 801996: 90th percentile AQI 771997: 90th percentile AQI 711998: 90th percentile AQI 1011999: 90th percentile AQI 972000: 90th percentile AQI 812001: 90th percentile AQI 852002: 90th percentile AQI 1052003: 90th percentile AQI 872004: 90th percentile AQI 742005: 90th percentile AQI 862006: 90th percentile AQI 832007: 90th percentile AQI 812008: 90th percentile AQI 842009: 90th percentile AQI 712010: 90th percentile AQI 872011: 90th percentile AQI 732012: 90th percentile AQI 692013: 90th percentile AQI 672014: 90th percentile AQI 622015: 90th percentile AQI 692016: 90th percentile AQI 612017: 90th percentile AQI 612018: 90th percentile AQI 622019: 90th percentile AQI 642020: 90th percentile AQI 632021: 90th percentile AQI 582022: 90th percentile AQI 602023: 90th percentile AQI 622024: 90th percentile AQI 602025: 90th percentile AQI 641980: Median AQI 311981: Median AQI 241982: Median AQI 301983: Median AQI 321984: Median AQI 231985: Median AQI 291986: Median AQI 291987: Median AQI 311988: Median AQI 311989: Median AQI 311990: Median AQI 311991: Median AQI 331992: Median AQI 311993: Median AQI 331994: Median AQI 361995: Median AQI 321996: Median AQI 321997: Median AQI 321998: Median AQI 341999: Median AQI 372000: Median AQI 402001: Median AQI 442002: Median AQI 432003: Median AQI 412004: Median AQI 402005: Median AQI 422006: Median AQI 422007: Median AQI 392008: Median AQI 432009: Median AQI 402010: Median AQI 442011: Median AQI 482012: Median AQI 442013: Median AQI 462014: Median AQI 442015: Median AQI 442016: Median AQI 432017: Median AQI 422018: Median AQI 432019: Median AQI 432020: Median AQI 402021: Median AQI 422022: Median AQI 422023: Median AQI 412024: Median AQI 382025: Median AQI 411980198519901995200020052010201520202025
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2025

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
Ozone25570%
Fine particles (PM2.5)11030%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253652659532004164154Ozone
20243662916960003860133Ozone
202336527874112004162195Ozone
20223652728580004260133Ozone
202136528173101004258154Ozone
20203662827860004063133Ozone
20193652768090004364150Ozone
2018365254100101004362172Ozone
20173652718572004261159Ozone
201636625410480004361150Ozone
2015365241110140004469150Ozone
201436524412010004462136Ozone
201336522513172004667159Ozone
201236523311994004469174Ozone
2011365201147124104873209Ozone
201036524793223004487166Ozone
20093652887061004071151Ozone
200836625390167004384190Ozone
200736526279195003981177Ozone
200636525791124104283226Ozone
200536525584179004286190Ozone
200436626981133004074161Ozone
200336526178203304187213Ozone
20023652447628125043105224Ozone
2001365234106176204485213Ozone
2000366246102133204081216Ozone
1999363275551613403797207Ozone
1998364280472692034101218Ozone
199736530533167403271214Ozone
199636430141148003277185Ozone
199536330238144503280212Ozone
19943552704627111036101205Ozone
1993365299351415203390247Ozone
199236630638156103180218Ozone
19913592684422196033108225Ozone
1990346281321513503193213Ozone
1989326266341210403187209Ozone
1988344288221613503193235Ozone
198735429723224803197238Ozone
198635529538127302974209Ozone
19853022602966102974201Ozone
198434333670000233687Ozone
198328821132191511032150233Ozone
19822942562891003058174Ozone
19813513151997102451201Ozone
198033624938211612031143258Ozone

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 2025

All monitored counties in New York

Source: U.S. EPA AirData, “Annual AQI by County” files for 1980–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem