Ithaca, NY Air Quality

EPA monitor data through 2025 · Updated September 02, 2026 · Methods

In 2025, Ithaca, NY recorded 0 days above an Air Quality Index of 100, the level at which EPA begins warning sensitive groups, out of 359 days with monitoring data. The rest of the year was 335 Good days and 24 Moderate days. Under the AQI rules that applied before 2013, the same air would have scored 0 days. Since 2000, unhealthy days are 100% lower on a consistent definition.

Unhealthy days, 2025
0
AQI above 100
Same air, pre-2013 rules
0
for comparison with older reports
Good-air days
335
AQI 50 or below
Days monitored
359
full year

Unhealthy days by year, scored two ways

EPA changed what an AQI of 100 means in 2013 and again in 2015, so a count published before those changes is not comparable to one published after. Each panel below applies a single fixed rulebook to every year, so each is internally consistent. Why this matters.

Scored by today's rules

Ithaca, NY: days above AQI 100 by year, current rules 0 6 12 18 24 2000 2005 2010 2015 2020 2025 2000: 10 days 2001: 20 days 2002: 22 days 2003: 7 days 2004: 2 days 2005: 11 days 2006: 1 days 2007: 4 days 2008: 3 days 2009: 0 days 2010: 4 days 2011: 0 days 2012: 6 days 2013: 0 days 2014: 0 days 2015: 0 days 2016: 2 days 2017: 0 days 2018: 1 days 2019: 0 days 2020: 0 days 2021: 1 days 2022: 0 days 2023: 0 days 2024: 0 days 2025: 0 days

Scored by the pre-2013 rules

Ithaca, NY: days above AQI 100 by year, pre-2013 rules 0 6 12 18 24 2000 2005 2010 2015 2020 2025 2000: 2 days 2001: 11 days 2002: 13 days 2003: 7 days 2004: 0 days 2005: 4 days 2006: 1 days 2007: 0 days 2008: 2 days 2009: 0 days 2010: 1 days 2011: 0 days 2012: 0 days 2013: 0 days 2014: 0 days 2015: 0 days 2016: 1 days 2017: 0 days 2018: 0 days 2019: 0 days 2020: 0 days 2021: 0 days 2022: 0 days 2023: 0 days 2024: 0 days 2025: 0 days

Ozone since 1990

The index counts above only start in 2000, because nationwide fine-particle monitoring did not exist before 1999 and an index without it would measure the monitoring network rather than the air. Ozone does have a 35-year record. This is Ithaca, NY's, from EPA's long-running trend monitors: 81 ppb in 1990 to 57 ppb in 2024, 30% lower.

Peak ozone, 1990 to 2024

Ithaca, NY: peak ozone by year since 1990, ppb 0 20 40 60 80 100 1994 2004 2014 2024 1990: 81 ppb 1991: 91 ppb 1992: 90 ppb 1993: 83 ppb 1994: 81 ppb 1995: 84 ppb 1996: 79 ppb 1997: 80 ppb 1998: 83 ppb 1999: 82 ppb 2000: 74 ppb 2001: 84 ppb 2002: 88 ppb 2003: 78 ppb 2004: 66 ppb 2005: 79 ppb 2006: 68 ppb 2007: 71 ppb 2008: 69 ppb 2009: 62 ppb 2010: 73 ppb 2011: 62 ppb 2012: 73 ppb 2013: 65 ppb 2014: 59 ppb 2015: 64 ppb 2016: 66 ppb 2017: 57 ppb 2018: 67 ppb 2019: 56 ppb 2020: 55 ppb 2021: 63 ppb 2022: 59 ppb 2023: 65 ppb 2024: 57 ppb 70 ppb standard
Annual fourth-highest daily maximum 8-hour ozone, parts per billion, averaged across 1 long-running monitor in the area. The dashed line is the current standard, 70 ppb. Holding the monitor set still is what makes a 35-year comparison meaningful, and it is also why these values differ from the design value used for compliance. Source: EPA air quality statistics by city.

What 2025 looked like

Air quality categoryDaysShare of days with an AQI
Good33593%
Moderate247%
Unhealthy for sensitive groups00%
Unhealthy or worse00%

Median AQI 35 · 90th-percentile AQI 47 · worst day 74. Scored under current rules, out of 359 days with an AQI.

Statewide context

Ithaca, NY sits in New York.

Days in each air quality category, by year

How many days fell in each AQI category, for every year with an AQI on record. Categories are scored under EPA's current breakpoints. A year with fewer than 300 days is marked, because a short year lowers every count for reasons that have nothing to do with the air.

YearGoodModerate Unhealthy for sensitive groupsUnhealthy or worse Days with an AQI
2000 3123510 0357
2001 2796519 1364
2002 2707118 4363
2003 263614 3331
2004 294592 0355
2005 2777710 1365
2006 320391 0360
2007 309484 0361
2008 334273 0364
2009 340190 0359
2010 313414 0358
2011 281200 0301
2012 312406 0358
2013 336230 0359
2014 344190 0363
2015 345180 0363
2016 337272 0366
2017 348140 0362
2018 337251 0363
2019 35670 0363
2020 36150 0366
2021 339251 0365
2022 354110 0365
2023 336230 0359
2024 349100 0359
2025 335240 0359

Good is AQI 0–50, Moderate 51–100, Unhealthy for sensitive groups 101–150. “Unhealthy or worse” combines the Unhealthy, Very Unhealthy and Hazardous categories, which are shown together because most areas record too few of each to report separately. The four columns sum to the last one by construction. These counts exclude sulphur dioxide, following EPA, which drops SO₂ from county and metro summaries because it is too localized to describe a whole area.

The full series

The same years scored two ways, with the pollutant that drove the days above 100. EPA's files record which pollutant set each day's AQI; they do not attribute days to wildfire smoke, so no column here claims to.

YearUnhealthy days, current rulesOf which ozone Of which fine particlesPre-2013 rulesDays monitored
200010 10 0 2357
200120 19 1 11364
200222 21 1 13363
20037 7 0 7331
20042 2 0 0355
200511 11 0 4365
20061 1 0 1360
20074 4 0 0361
20083 3 0 2364
20090 0 0 0359
20104 4 0 1358
20110 0 0 0301
20126 6 0 0358
20130 0 0 0359
20140 0 0 0363
20150 0 0 0363
20162 2 0 1366
20170 0 0 0365
20181 1 0 0365
20190 0 0 0365
20200 0 0 0366
20211 1 0 0365
20220 0 0 0365
20230 0 0 0359
20240 0 0 0359
20250 0 0 0359

Sources