EnviroNearby

Racine County, Wisconsin air quality history

Daily Air Quality Index summaries from EPA monitors in Racine, Wisconsin, 1980–2025.

76%
Good days in 2025
41
Median daily AQI, 2025
8
Days above 100 in 2025
199
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Racine, Wisconsin on 199 days. 151 of those days (76%) were in the Good range, and the median daily AQI was 41. That median is higher than the typical monitored county in Wisconsin (median 38 across 29 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 199 days. Across the years with fuller monitoring, the share of Good days fell: an average of 84% in 1980–1982 versus 73% in 2023–2025.

EPA did not report an AQI for every day of 2025 here (199 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.

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 305 of 360 days1980: Moderate 28 of 360 days1980: Unhealthy for Sensitive Groups 14 of 360 days1980: Unhealthy 9 of 360 days1980: Very Unhealthy 4 of 360 days19801981: Good 305 of 357 days1981: Moderate 23 of 357 days1981: Unhealthy for Sensitive Groups 14 of 357 days1981: Unhealthy 8 of 357 days1981: Very Unhealthy 7 of 357 days1982: Good 300 of 365 days1982: Moderate 39 of 365 days1982: Unhealthy for Sensitive Groups 16 of 365 days1982: Unhealthy 10 of 365 days1983: Good 289 of 359 days1983: Moderate 30 of 359 days1983: Unhealthy for Sensitive Groups 19 of 359 days1983: Unhealthy 10 of 359 days1983: Very Unhealthy 11 of 359 days1984: Good 313 of 365 days1984: Moderate 30 of 365 days1984: Unhealthy for Sensitive Groups 8 of 365 days1984: Unhealthy 8 of 365 days1984: Very Unhealthy 6 of 365 days1985: Good 315 of 365 days1985: Moderate 30 of 365 days1985: Unhealthy for Sensitive Groups 12 of 365 days1985: Unhealthy 7 of 365 days1985: Very Unhealthy 1 of 365 days19851986: Good 318 of 365 days1986: Moderate 27 of 365 days1986: Unhealthy for Sensitive Groups 10 of 365 days1986: Unhealthy 10 of 365 days1987: Good 286 of 365 days1987: Moderate 39 of 365 days1987: Unhealthy for Sensitive Groups 22 of 365 days1987: Unhealthy 12 of 365 days1987: Very Unhealthy 6 of 365 days1988: Good 260 of 366 days1988: Moderate 58 of 366 days1988: Unhealthy for Sensitive Groups 20 of 366 days1988: Unhealthy 12 of 366 days1988: Very Unhealthy 16 of 366 days1989: Good 274 of 364 days1989: Moderate 60 of 364 days1989: Unhealthy for Sensitive Groups 15 of 364 days1989: Unhealthy 10 of 364 days1989: Very Unhealthy 5 of 364 days1990: Good 303 of 365 days1990: Moderate 40 of 365 days1990: Unhealthy for Sensitive Groups 18 of 365 days1990: Unhealthy 4 of 365 days19901991: Good 295 of 365 days1991: Moderate 40 of 365 days1991: Unhealthy for Sensitive Groups 18 of 365 days1991: Unhealthy 10 of 365 days1991: Very Unhealthy 2 of 365 days1992: Good 330 of 366 days1992: Moderate 26 of 366 days1992: Unhealthy for Sensitive Groups 7 of 366 days1992: Unhealthy 2 of 366 days1992: Very Unhealthy 1 of 366 days1993: Good 330 of 365 days1993: Moderate 27 of 365 days1993: Unhealthy for Sensitive Groups 6 of 365 days1993: Unhealthy 2 of 365 days1994: Good 323 of 364 days1994: Moderate 29 of 364 days1994: Unhealthy for Sensitive Groups 7 of 364 days1994: Unhealthy 4 of 364 days1994: Very Unhealthy 1 of 364 days1995: Good 315 of 365 days1995: Moderate 33 of 365 days1995: Unhealthy for Sensitive Groups 7 of 365 days1995: Unhealthy 9 of 365 days1995: Very Unhealthy 1 of 365 days19951996: Good 337 of 366 days1996: Moderate 16 of 366 days1996: Unhealthy for Sensitive Groups 11 of 366 days1996: Very Unhealthy 2 of 366 days1997: Good 322 of 363 days1997: Moderate 28 of 363 days1997: Unhealthy for Sensitive Groups 8 of 363 days1997: Unhealthy 4 of 363 days1997: Very Unhealthy 1 of 363 days1998: Good 295 of 365 days1998: Moderate 49 of 365 days1998: Unhealthy for Sensitive Groups 18 of 365 days1998: Unhealthy 1 of 365 days1998: Very Unhealthy 2 of 365 days1999: Good 308 of 364 days1999: Moderate 33 of 364 days1999: Unhealthy for Sensitive Groups 17 of 364 days1999: Unhealthy 6 of 364 days2000: Good 321 of 362 days2000: Moderate 32 of 362 days2000: Unhealthy for Sensitive Groups 8 of 362 days2000: Unhealthy 1 of 362 days20002001: Good 319 of 365 days2001: Moderate 29 of 365 days2001: Unhealthy for Sensitive Groups 12 of 365 days2001: Unhealthy 4 of 365 days2001: Very Unhealthy 1 of 365 days2002: Good 314 of 365 days2002: Moderate 26 of 365 days2002: Unhealthy for Sensitive Groups 14 of 365 days2002: Unhealthy 7 of 365 days2002: Very Unhealthy 4 of 365 days2003: Good 156 of 200 days2003: Moderate 32 of 200 days2003: Unhealthy for Sensitive Groups 12 of 200 days2004: Good 154 of 182 days2004: Moderate 26 of 182 days2004: Unhealthy for Sensitive Groups 1 of 182 days2004: Unhealthy 1 of 182 days2005: Good 131 of 185 days2005: Moderate 34 of 185 days2005: Unhealthy for Sensitive Groups 13 of 185 days2005: Unhealthy 7 of 185 days20052006: Good 153 of 184 days2006: Moderate 26 of 184 days2006: Unhealthy for Sensitive Groups 5 of 184 days2007: Good 123 of 175 days2007: Moderate 40 of 175 days2007: Unhealthy for Sensitive Groups 12 of 175 days2008: Good 156 of 183 days2008: Moderate 27 of 183 days2009: Good 154 of 177 days2009: Moderate 19 of 177 days2009: Unhealthy for Sensitive Groups 3 of 177 days2009: Unhealthy 1 of 177 days2010: Good 144 of 192 days2010: Moderate 42 of 192 days2010: Unhealthy for Sensitive Groups 6 of 192 days20102011: Good 150 of 192 days2011: Moderate 35 of 192 days2011: Unhealthy for Sensitive Groups 5 of 192 days2011: Unhealthy 2 of 192 days2012: Good 126 of 187 days2012: Moderate 34 of 187 days2012: Unhealthy for Sensitive Groups 22 of 187 days2012: Unhealthy 5 of 187 days2013: Good 156 of 186 days2013: Moderate 30 of 186 days2015: Good 154 of 185 days2015: Moderate 30 of 185 days2015: Unhealthy for Sensitive Groups 1 of 185 days2016: Good 153 of 197 days2016: Moderate 35 of 197 days2016: Unhealthy for Sensitive Groups 8 of 197 days2016: Unhealthy 1 of 197 days20162017: Good 176 of 230 days2017: Moderate 43 of 230 days2017: Unhealthy for Sensitive Groups 11 of 230 days2018: Good 187 of 236 days2018: Moderate 38 of 236 days2018: Unhealthy for Sensitive Groups 9 of 236 days2018: Unhealthy 2 of 236 days2019: Good 174 of 203 days2019: Moderate 28 of 203 days2019: Unhealthy for Sensitive Groups 1 of 203 days2020: Good 162 of 199 days2020: Moderate 29 of 199 days2020: Unhealthy for Sensitive Groups 7 of 199 days2020: Unhealthy 1 of 199 days2021: Good 149 of 210 days2021: Moderate 53 of 210 days2021: Unhealthy for Sensitive Groups 8 of 210 days20212022: Good 165 of 202 days2022: Moderate 34 of 202 days2022: Unhealthy for Sensitive Groups 2 of 202 days2022: Unhealthy 1 of 202 days2023: Good 138 of 203 days2023: Moderate 49 of 203 days2023: Unhealthy for Sensitive Groups 14 of 203 days2023: Unhealthy 2 of 203 days2024: Good 156 of 205 days2024: Moderate 38 of 205 days2024: Unhealthy for Sensitive Groups 10 of 205 days2024: Unhealthy 1 of 205 days2025: Good 151 of 199 days2025: Moderate 40 of 199 days2025: Unhealthy for Sensitive Groups 8 of 199 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 901981: 90th percentile AQI 801982: 90th percentile AQI 741983: 90th percentile AQI 1051984: 90th percentile AQI 741985: 90th percentile AQI 671986: 90th percentile AQI 711987: 90th percentile AQI 1081988: 90th percentile AQI 1291989: 90th percentile AQI 871990: 90th percentile AQI 741991: 90th percentile AQI 901992: 90th percentile AQI 501993: 90th percentile AQI 491994: 90th percentile AQI 541995: 90th percentile AQI 611996: 90th percentile AQI 481997: 90th percentile AQI 541998: 90th percentile AQI 801999: 90th percentile AQI 772000: 90th percentile AQI 542001: 90th percentile AQI 582002: 90th percentile AQI 712003: 90th percentile AQI 872004: 90th percentile AQI 672005: 90th percentile AQI 1052006: 90th percentile AQI 672007: 90th percentile AQI 902008: 90th percentile AQI 612009: 90th percentile AQI 582010: 90th percentile AQI 842011: 90th percentile AQI 672012: 90th percentile AQI 1222013: 90th percentile AQI 582015: 90th percentile AQI 672016: 90th percentile AQI 772017: 90th percentile AQI 842018: 90th percentile AQI 772019: 90th percentile AQI 582020: 90th percentile AQI 672021: 90th percentile AQI 802022: 90th percentile AQI 672023: 90th percentile AQI 972024: 90th percentile AQI 802025: 90th percentile AQI 771980: Median AQI 261981: Median AQI 271982: Median AQI 281983: Median AQI 301984: Median AQI 291985: Median AQI 261986: Median AQI 251987: Median AQI 311988: Median AQI 381989: Median AQI 361990: Median AQI 341991: Median AQI 321992: Median AQI 301993: Median AQI 271994: Median AQI 291995: Median AQI 251996: Median AQI 241997: Median AQI 251998: Median AQI 251999: Median AQI 242000: Median AQI 222001: Median AQI 202002: Median AQI 212003: Median AQI 382004: Median AQI 352005: Median AQI 422006: Median AQI 382007: Median AQI 422008: Median AQI 392009: Median AQI 372010: Median AQI 422011: Median AQI 402012: Median AQI 422013: Median AQI 382015: Median AQI 392016: Median AQI 422017: Median AQI 422018: Median AQI 422019: Median AQI 392020: Median AQI 382021: Median AQI 432022: Median AQI 402023: Median AQI 442024: Median AQI 422025: Median AQI 411980198519901995200020052010201620212025
  • 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
Ozone199100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20251991514080004177122Ozone
202420515638101004280151Ozone
202320313849142004497200Ozone
20222021653421004067164Ozone
20212101495380004380126Ozone
20201991622971003867172Ozone
20192031742810003958115Ozone
20182361873892004277161Ozone
201723017643110004284143Ozone
20161971533581004277169Ozone
20151851543010003967105Ozone
2013186156300000385893Ozone
2012187126342250042122177Ozone
20111921503552004067190Ozone
20101921444260004284147Ozone
20091771541931003758161Ozone
20081831562700003961100Ozone
200717512340120004290150Ozone
20061841532650003867133Ozone
2005185131341370042105182Ozone
20041821542611003567164Ozone
200320015632120003887147Ozone
200236531426147402171209CO
200136531929124102058203CO
20003623213281002254154Ozone
199936430833176002477185Ozone
199836529549181202580207CO
19973633222884102554217Ozone
199636633716110202448207CO
19953653153379102561202CO
19943643232974102954232CO
19933653302762002749174CO
19923663302672103050218CO
1991365295401810203290223CO
199036530340184003474182CO
1989364274601510503687225CO
198836626058201216038129263CO
19873652863922126031108253Ozone
1986365318271010002571192CO
198536531530127102667206CO
19843653133088602974247CO
198335928930191011030105256CO
1982365300391610002874200CO
198135730523148702780245Ozone
198036030528149402690236Ozone

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 Wisconsin with a similar median AQI in 2025

All monitored counties in Wisconsin

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