EnviroNearby

Tompkins County, New York air quality history

Daily Air Quality Index summaries from EPA monitors in Tompkins, New York, 1990–2025.

93%
Good days in 2025
35
Median daily AQI, 2025
0
Days above 100 in 2025
355
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Tompkins, New York on 355 days. 331 of those days (93%) were in the Good range, and the median daily AQI was 35. That median is about the same as the typical monitored county in New York (median 36 across 27 counties), and lower than the typical monitored U.S. county (40). The main pollutant was ozone on 355 days. Across the years with fuller monitoring, the share of Good days rose: an average of 79% in 1990–1992 versus 94% 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%1990: Good 271 of 348 days1990: Moderate 60 of 348 days1990: Unhealthy for Sensitive Groups 16 of 348 days1990: Unhealthy 1 of 348 days19901991: Good 263 of 362 days1991: Moderate 58 of 362 days1991: Unhealthy for Sensitive Groups 35 of 362 days1991: Unhealthy 6 of 362 days1992: Good 311 of 364 days1992: Moderate 37 of 364 days1992: Unhealthy for Sensitive Groups 12 of 364 days1992: Unhealthy 4 of 364 days1993: Good 206 of 292 days1993: Moderate 65 of 292 days1993: Unhealthy for Sensitive Groups 18 of 292 days1993: Unhealthy 3 of 292 days1994: Good 173 of 244 days1994: Moderate 57 of 244 days1994: Unhealthy for Sensitive Groups 13 of 244 days1994: Unhealthy 1 of 244 days1995: Good 199 of 269 days1995: Moderate 50 of 269 days1995: Unhealthy for Sensitive Groups 19 of 269 days1995: Unhealthy 1 of 269 days19951996: Good 157 of 205 days1996: Moderate 38 of 205 days1996: Unhealthy for Sensitive Groups 9 of 205 days1996: Unhealthy 1 of 205 days1997: Good 275 of 360 days1997: Moderate 68 of 360 days1997: Unhealthy for Sensitive Groups 17 of 360 days1998: Good 260 of 360 days1998: Moderate 67 of 360 days1998: Unhealthy for Sensitive Groups 29 of 360 days1998: Unhealthy 4 of 360 days1999: Good 258 of 348 days1999: Moderate 70 of 348 days1999: Unhealthy for Sensitive Groups 20 of 348 days2000: Good 297 of 348 days2000: Moderate 40 of 348 days2000: Unhealthy for Sensitive Groups 11 of 348 days20002001: Good 272 of 359 days2001: Moderate 65 of 359 days2001: Unhealthy for Sensitive Groups 21 of 359 days2001: Unhealthy 1 of 359 days2002: Good 265 of 361 days2002: Moderate 73 of 361 days2002: Unhealthy for Sensitive Groups 17 of 361 days2002: Unhealthy 6 of 361 days2003: Good 249 of 322 days2003: Moderate 66 of 322 days2003: Unhealthy for Sensitive Groups 4 of 322 days2003: Unhealthy 3 of 322 days2004: Good 290 of 352 days2004: Moderate 60 of 352 days2004: Unhealthy for Sensitive Groups 2 of 352 days2005: Good 274 of 363 days2005: Moderate 77 of 363 days2005: Unhealthy for Sensitive Groups 10 of 363 days2005: Unhealthy 2 of 363 days20052006: Good 304 of 348 days2006: Moderate 43 of 348 days2006: Unhealthy for Sensitive Groups 1 of 348 days2007: Good 302 of 356 days2007: Moderate 50 of 356 days2007: Unhealthy for Sensitive Groups 4 of 356 days2008: Good 330 of 361 days2008: Moderate 28 of 361 days2008: Unhealthy for Sensitive Groups 3 of 361 days2009: Good 328 of 347 days2009: Moderate 19 of 347 days2010: Good 298 of 345 days2010: Moderate 43 of 345 days2010: Unhealthy for Sensitive Groups 4 of 345 days20102011: Good 269 of 289 days2011: Moderate 20 of 289 days2012: Good 305 of 350 days2012: Moderate 39 of 350 days2012: Unhealthy for Sensitive Groups 6 of 350 days2013: Good 327 of 351 days2013: Moderate 24 of 351 days2014: Good 334 of 353 days2014: Moderate 19 of 353 days2015: Good 332 of 351 days2015: Moderate 19 of 351 days20152016: Good 331 of 361 days2016: Moderate 28 of 361 days2016: Unhealthy for Sensitive Groups 2 of 361 days2017: Good 339 of 353 days2017: Moderate 14 of 353 days2018: Good 332 of 360 days2018: Moderate 27 of 360 days2018: Unhealthy for Sensitive Groups 1 of 360 days2019: Good 349 of 356 days2019: Moderate 7 of 356 days2020: Good 359 of 364 days2020: Moderate 5 of 364 days20202021: Good 334 of 360 days2021: Moderate 25 of 360 days2021: Unhealthy for Sensitive Groups 1 of 360 days2022: Good 349 of 361 days2022: Moderate 12 of 361 days2023: Good 332 of 357 days2023: Moderate 25 of 357 days2024: Good 340 of 350 days2024: Moderate 10 of 350 days2025: Good 331 of 355 days2025: Moderate 24 of 355 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 year0501001501990: 90th percentile AQI 801991: 90th percentile AQI 1051992: 90th percentile AQI 741993: 90th percentile AQI 931994: 90th percentile AQI 901995: 90th percentile AQI 901996: 90th percentile AQI 871997: 90th percentile AQI 771998: 90th percentile AQI 1001999: 90th percentile AQI 872000: 90th percentile AQI 672001: 90th percentile AQI 802002: 90th percentile AQI 872003: 90th percentile AQI 682004: 90th percentile AQI 582005: 90th percentile AQI 772006: 90th percentile AQI 542007: 90th percentile AQI 612008: 90th percentile AQI 492009: 90th percentile AQI 472010: 90th percentile AQI 582011: 90th percentile AQI 492012: 90th percentile AQI 542013: 90th percentile AQI 482014: 90th percentile AQI 452015: 90th percentile AQI 482016: 90th percentile AQI 482017: 90th percentile AQI 452018: 90th percentile AQI 472019: 90th percentile AQI 452020: 90th percentile AQI 442021: 90th percentile AQI 482022: 90th percentile AQI 442023: 90th percentile AQI 472024: 90th percentile AQI 472025: 90th percentile AQI 471990: Median AQI 371991: Median AQI 381992: Median AQI 351993: Median AQI 411994: Median AQI 401995: Median AQI 431996: Median AQI 351997: Median AQI 391998: Median AQI 401999: Median AQI 412000: Median AQI 382001: Median AQI 402002: Median AQI 382003: Median AQI 382004: Median AQI 372005: Median AQI 412006: Median AQI 352007: Median AQI 352008: Median AQI 342009: Median AQI 342010: Median AQI 372011: Median AQI 352012: Median AQI 372013: Median AQI 352014: Median AQI 352015: Median AQI 352016: Median AQI 362017: Median AQI 352018: Median AQI 332019: Median AQI 352020: Median AQI 342021: Median AQI 352022: Median AQI 362023: Median AQI 352024: Median AQI 352025: Median AQI 3519901995200020052010201520202025
  • 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
Ozone355100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025355331240000354774Ozone
2024350340100000354771Ozone
20233573322500003547100Ozone
2022361349120000364467Ozone
20213603342510003548105Ozone
202036435950000344464Ozone
201935634970000354561Ozone
20183603322710003347101Ozone
2017353339140000354571Ozone
20163613312820003648122Ozone
2015351332190000354893Ozone
2014353334190000354580Ozone
2013351327240000354893Ozone
20123503053960003754115Ozone
2011289269200000354990Ozone
20103452984340003758122Ozone
2009347328190000344793Ozone
20083613302830003449150Ozone
20073563025040003561115Ozone
20063483044310003554119Ozone
200536327477102004177151Ozone
20043522906020003758108Ozone
20033222496643003868177Ozone
200236126573176003887192Ozone
200135927265211004080151Ozone
200034829740110003867150Ozone
199934825870200004187150Ozone
1998360260672940040100177Ozone
199736027568170003977150Ozone
19962051573891003587151Ozone
199526919950191004390159Ozone
199424417357131004090154Ozone
199329220665183004193190Ozone
199236431137124003574179Ozone
1991362263583560038105192Ozone
199034827160161003780154Ozone

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 1990–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem