EnviroNearby

Kenosha County, Wisconsin air quality history

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

69%
Good days in 2025
42
Median daily AQI, 2025
19
Days above 100 in 2025
347
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Kenosha, Wisconsin on 347 days. 240 of those days (69%) were in the Good range, and the median daily AQI was 42. 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 198 days. Across the years with fuller monitoring, the share of Good days fell: an average of 80% in 1980–1982 versus 66% 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 283 of 366 days1980: Moderate 60 of 366 days1980: Unhealthy for Sensitive Groups 16 of 366 days1980: Unhealthy 6 of 366 days1980: Very Unhealthy 1 of 366 days19801981: Good 278 of 355 days1981: Moderate 51 of 355 days1981: Unhealthy for Sensitive Groups 15 of 355 days1981: Unhealthy 6 of 355 days1981: Very Unhealthy 5 of 355 days1982: Good 302 of 363 days1982: Moderate 52 of 363 days1982: Unhealthy for Sensitive Groups 7 of 363 days1982: Unhealthy 2 of 363 days1983: Good 275 of 361 days1983: Moderate 56 of 361 days1983: Unhealthy for Sensitive Groups 14 of 361 days1983: Unhealthy 12 of 361 days1983: Very Unhealthy 4 of 361 days1984: Good 238 of 288 days1984: Moderate 30 of 288 days1984: Unhealthy for Sensitive Groups 13 of 288 days1984: Unhealthy 5 of 288 days1984: Very Unhealthy 2 of 288 days1985: Good 284 of 364 days1985: Moderate 66 of 364 days1985: Unhealthy for Sensitive Groups 10 of 364 days1985: Unhealthy 3 of 364 days1985: Very Unhealthy 1 of 364 days19851986: Good 98 of 358 days1986: Moderate 195 of 358 days1986: Unhealthy for Sensitive Groups 62 of 358 days1986: Unhealthy 3 of 358 days1987: Good 225 of 337 days1987: Moderate 77 of 337 days1987: Unhealthy for Sensitive Groups 23 of 337 days1987: Unhealthy 6 of 337 days1987: Very Unhealthy 6 of 337 days1988: Good 245 of 333 days1988: Moderate 32 of 333 days1988: Unhealthy for Sensitive Groups 20 of 333 days1988: Unhealthy 16 of 333 days1988: Very Unhealthy 20 of 333 days1989: Good 258 of 358 days1989: Moderate 56 of 358 days1989: Unhealthy for Sensitive Groups 25 of 358 days1989: Unhealthy 16 of 358 days1989: Very Unhealthy 3 of 358 days1990: Good 286 of 363 days1990: Moderate 48 of 363 days1990: Unhealthy for Sensitive Groups 21 of 363 days1990: Unhealthy 8 of 363 days19901991: Good 268 of 365 days1991: Moderate 38 of 365 days1991: Unhealthy for Sensitive Groups 28 of 365 days1991: Unhealthy 24 of 365 days1991: Very Unhealthy 7 of 365 days1992: Good 232 of 289 days1992: Moderate 34 of 289 days1992: Unhealthy for Sensitive Groups 15 of 289 days1992: Unhealthy 6 of 289 days1992: Very Unhealthy 2 of 289 days1993: Good 132 of 184 days1993: Moderate 36 of 184 days1993: Unhealthy for Sensitive Groups 12 of 184 days1993: Unhealthy 3 of 184 days1993: Very Unhealthy 1 of 184 days1994: Good 123 of 184 days1994: Moderate 38 of 184 days1994: Unhealthy for Sensitive Groups 17 of 184 days1994: Unhealthy 4 of 184 days1994: Very Unhealthy 2 of 184 days1995: Good 100 of 183 days1995: Moderate 43 of 183 days1995: Unhealthy for Sensitive Groups 23 of 183 days1995: Unhealthy 11 of 183 days1995: Very Unhealthy 6 of 183 days19951996: Good 120 of 184 days1996: Moderate 43 of 184 days1996: Unhealthy for Sensitive Groups 16 of 184 days1996: Unhealthy 3 of 184 days1996: Very Unhealthy 2 of 184 days1997: Good 125 of 197 days1997: Moderate 51 of 197 days1997: Unhealthy for Sensitive Groups 15 of 197 days1997: Unhealthy 5 of 197 days1997: Very Unhealthy 1 of 197 days1998: Good 81 of 208 days1998: Moderate 91 of 208 days1998: Unhealthy for Sensitive Groups 23 of 208 days1998: Unhealthy 11 of 208 days1998: Very Unhealthy 2 of 208 days1999: Good 124 of 241 days1999: Moderate 80 of 241 days1999: Unhealthy for Sensitive Groups 26 of 241 days1999: Unhealthy 11 of 241 days2000: Good 140 of 244 days2000: Moderate 89 of 244 days2000: Unhealthy for Sensitive Groups 11 of 244 days2000: Unhealthy 4 of 244 days20002001: Good 118 of 245 days2001: Moderate 95 of 245 days2001: Unhealthy for Sensitive Groups 17 of 245 days2001: Unhealthy 14 of 245 days2001: Very Unhealthy 1 of 245 days2002: Good 128 of 245 days2002: Moderate 83 of 245 days2002: Unhealthy for Sensitive Groups 17 of 245 days2002: Unhealthy 12 of 245 days2002: Very Unhealthy 5 of 245 days2003: Good 141 of 246 days2003: Moderate 83 of 246 days2003: Unhealthy for Sensitive Groups 18 of 246 days2003: Unhealthy 4 of 246 days2004: Good 152 of 244 days2004: Moderate 84 of 244 days2004: Unhealthy for Sensitive Groups 6 of 244 days2004: Unhealthy 2 of 244 days2005: Good 119 of 243 days2005: Moderate 97 of 243 days2005: Unhealthy for Sensitive Groups 16 of 243 days2005: Unhealthy 11 of 243 days20052006: Good 141 of 247 days2006: Moderate 99 of 247 days2006: Unhealthy for Sensitive Groups 6 of 247 days2006: Unhealthy 1 of 247 days2007: Good 119 of 245 days2007: Moderate 106 of 245 days2007: Unhealthy for Sensitive Groups 17 of 245 days2007: Unhealthy 3 of 245 days2008: Good 157 of 261 days2008: Moderate 98 of 261 days2008: Unhealthy for Sensitive Groups 6 of 261 days2009: Good 188 of 267 days2009: Moderate 73 of 267 days2009: Unhealthy for Sensitive Groups 5 of 267 days2009: Unhealthy 1 of 267 days2010: Good 181 of 309 days2010: Moderate 115 of 309 days2010: Unhealthy for Sensitive Groups 11 of 309 days2010: Unhealthy 2 of 309 days20102011: Good 187 of 301 days2011: Moderate 102 of 301 days2011: Unhealthy for Sensitive Groups 10 of 301 days2011: Unhealthy 2 of 301 days2012: Good 159 of 309 days2012: Moderate 117 of 309 days2012: Unhealthy for Sensitive Groups 24 of 309 days2012: Unhealthy 9 of 309 days2013: Good 161 of 338 days2013: Moderate 168 of 338 days2013: Unhealthy for Sensitive Groups 9 of 338 days2014: Good 177 of 363 days2014: Moderate 176 of 363 days2014: Unhealthy for Sensitive Groups 10 of 363 days2015: Good 221 of 361 days2015: Moderate 134 of 361 days2015: Unhealthy for Sensitive Groups 5 of 361 days2015: Unhealthy 1 of 361 days20152016: Good 253 of 362 days2016: Moderate 94 of 362 days2016: Unhealthy for Sensitive Groups 13 of 362 days2016: Unhealthy 2 of 362 days2017: Good 247 of 360 days2017: Moderate 103 of 360 days2017: Unhealthy for Sensitive Groups 10 of 360 days2018: Good 230 of 365 days2018: Moderate 121 of 365 days2018: Unhealthy for Sensitive Groups 11 of 365 days2018: Unhealthy 3 of 365 days2019: Good 248 of 365 days2019: Moderate 115 of 365 days2019: Unhealthy for Sensitive Groups 2 of 365 days2020: Good 238 of 361 days2020: Moderate 112 of 361 days2020: Unhealthy for Sensitive Groups 10 of 361 days2020: Unhealthy 1 of 361 days20202021: Good 197 of 344 days2021: Moderate 136 of 344 days2021: Unhealthy for Sensitive Groups 11 of 344 days2022: Good 236 of 365 days2022: Moderate 124 of 365 days2022: Unhealthy for Sensitive Groups 4 of 365 days2022: Unhealthy 1 of 365 days2023: Good 201 of 365 days2023: Moderate 139 of 365 days2023: Unhealthy for Sensitive Groups 20 of 365 days2023: Unhealthy 4 of 365 days2023: Very Unhealthy 1 of 365 days2024: Good 267 of 366 days2024: Moderate 88 of 366 days2024: Unhealthy for Sensitive Groups 11 of 366 days2025: Good 240 of 347 days2025: Moderate 88 of 347 days2025: Unhealthy for Sensitive Groups 18 of 347 days2025: Unhealthy 1 of 347 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 year0501001502001980: 90th percentile AQI 791981: 90th percentile AQI 901982: 90th percentile AQI 641983: 90th percentile AQI 901984: 90th percentile AQI 741985: 90th percentile AQI 741986: 90th percentile AQI 1031987: 90th percentile AQI 1011988: 90th percentile AQI 1511989: 90th percentile AQI 1081990: 90th percentile AQI 901991: 90th percentile AQI 1361992: 90th percentile AQI 901993: 90th percentile AQI 901994: 90th percentile AQI 1081995: 90th percentile AQI 1501996: 90th percentile AQI 1081997: 90th percentile AQI 1011998: 90th percentile AQI 1361999: 90th percentile AQI 1262000: 90th percentile AQI 872001: 90th percentile AQI 1192002: 90th percentile AQI 1262003: 90th percentile AQI 1002004: 90th percentile AQI 802005: 90th percentile AQI 1032006: 90th percentile AQI 802007: 90th percentile AQI 972008: 90th percentile AQI 782009: 90th percentile AQI 712010: 90th percentile AQI 842011: 90th percentile AQI 742012: 90th percentile AQI 1052013: 90th percentile AQI 732014: 90th percentile AQI 752015: 90th percentile AQI 672016: 90th percentile AQI 672017: 90th percentile AQI 742018: 90th percentile AQI 742019: 90th percentile AQI 652020: 90th percentile AQI 672021: 90th percentile AQI 742022: 90th percentile AQI 692023: 90th percentile AQI 872024: 90th percentile AQI 652025: 90th percentile AQI 771980: Median AQI 351981: Median AQI 341982: Median AQI 321983: Median AQI 341984: Median AQI 351985: Median AQI 351986: Median AQI 651987: Median AQI 371988: Median AQI 381989: Median AQI 391990: Median AQI 321991: Median AQI 341992: Median AQI 371993: Median AQI 421994: Median AQI 441995: Median AQI 481996: Median AQI 451997: Median AQI 461998: Median AQI 581999: Median AQI 502000: Median AQI 472001: Median AQI 522002: Median AQI 482003: Median AQI 472004: Median AQI 442005: Median AQI 522006: Median AQI 472007: Median AQI 512008: Median AQI 462009: Median AQI 412010: Median AQI 472011: Median AQI 442012: Median AQI 502013: Median AQI 512014: Median AQI 512015: Median AQI 452016: Median AQI 432017: Median AQI 432018: Median AQI 442019: Median AQI 442020: Median AQI 432021: Median AQI 472022: Median AQI 442023: Median AQI 482024: Median AQI 412025: Median AQI 421980198519901995200020052010201520202025
  • 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
Ozone19857%
Fine particles (PM2.5)14943%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202534724088181004277167Ozone
202436626788110004165143Ozone
2023365201139204104887206PM2.5
202236523612441004469164Ozone
2021344197136110004774136PM2.5
2020361238112101004367197Ozone
201936524811520004465119Ozone
2018365230121113004474166Ozone
2017360247103100004374147Ozone
201636225394132004367161Ozone
201536122113451004567160PM2.5
2014363177176100005175136PM2.5
201333816116890005173133PM2.5
20123091591172490050105192Ozone
2011301187102102004474177Ozone
2010309181115112004784159Ozone
20092671887351004171151Ozone
20082611579860004678126Ozone
2007245119106173005197174Ozone
20062471419961004780164Ozone
20052431199716110052103195Ozone
20042441528462004480179Ozone
2003246141831840047100179Ozone
20022451288317125048126223Ozone
20012451189517141052119209Ozone
200024414089114004787159Ozone
19992411248026110050126195Ozone
1998208819123112058136217Ozone
1997197125511551046101216Ozone
1996184120431632045108218Ozone
19951831004323116048150216Ozone
1994184123381742044108240Ozone
199318413236123104290203Ozone
199228923234156203790237Ozone
19913652683828247034136224Ozone
199036328648218003290195Ozone
19893582585625163039108227Ozone
198833324532201620038151265Ozone
1987337225772366037101261NO2
1986358981956230065103179NO2
198536428466103103574202NO2
198428823830135203574208Ozone
1983361275561412403490242NO2
19823633025272003264177NO2
198135527851156503490230NO2
198036628360166103579242NO2

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