EnviroNearby

Kent County, Michigan air quality history

Daily Air Quality Index summaries from EPA monitors in Kent, Michigan, 1980–2025.

42%
Good days in 2025
52
Median daily AQI, 2025
9
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 Kent, Michigan on 365 days. 153 of those days (42%) were in the Good range, and the median daily AQI was 52. That median is higher than the typical monitored county in Michigan (median 39 across 26 counties), and higher than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 306 days. Across the years with fuller monitoring, the share of Good days fell: an average of 78% in 1980–1982 versus 48% 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 265 of 366 days1980: Moderate 67 of 366 days1980: Unhealthy for Sensitive Groups 20 of 366 days1980: Unhealthy 14 of 366 days19801981: Good 297 of 364 days1981: Moderate 43 of 364 days1981: Unhealthy for Sensitive Groups 19 of 364 days1981: Unhealthy 4 of 364 days1981: Very Unhealthy 1 of 364 days1982: Good 288 of 365 days1982: Moderate 49 of 365 days1982: Unhealthy for Sensitive Groups 21 of 365 days1982: Unhealthy 7 of 365 days1983: Good 278 of 359 days1983: Moderate 42 of 359 days1983: Unhealthy for Sensitive Groups 27 of 359 days1983: Unhealthy 9 of 359 days1983: Very Unhealthy 3 of 359 days1984: Good 292 of 354 days1984: Moderate 37 of 354 days1984: Unhealthy for Sensitive Groups 16 of 354 days1984: Unhealthy 9 of 354 days1985: Good 302 of 365 days1985: Moderate 43 of 365 days1985: Unhealthy for Sensitive Groups 16 of 365 days1985: Unhealthy 3 of 365 days1985: Very Unhealthy 1 of 365 days19851986: Good 301 of 365 days1986: Moderate 41 of 365 days1986: Unhealthy for Sensitive Groups 16 of 365 days1986: Unhealthy 7 of 365 days1987: Good 277 of 365 days1987: Moderate 49 of 365 days1987: Unhealthy for Sensitive Groups 22 of 365 days1987: Unhealthy 13 of 365 days1987: Very Unhealthy 4 of 365 days1988: Good 279 of 366 days1988: Moderate 32 of 366 days1988: Unhealthy for Sensitive Groups 22 of 366 days1988: Unhealthy 23 of 366 days1988: Very Unhealthy 10 of 366 days1989: Good 270 of 365 days1989: Moderate 54 of 365 days1989: Unhealthy for Sensitive Groups 26 of 365 days1989: Unhealthy 13 of 365 days1989: Very Unhealthy 2 of 365 days1990: Good 294 of 365 days1990: Moderate 41 of 365 days1990: Unhealthy for Sensitive Groups 22 of 365 days1990: Unhealthy 7 of 365 days1990: Very Unhealthy 1 of 365 days19901991: Good 290 of 365 days1991: Moderate 35 of 365 days1991: Unhealthy for Sensitive Groups 28 of 365 days1991: Unhealthy 11 of 365 days1991: Very Unhealthy 1 of 365 days1992: Good 308 of 366 days1992: Moderate 45 of 366 days1992: Unhealthy for Sensitive Groups 10 of 366 days1992: Unhealthy 3 of 366 days1993: Good 317 of 365 days1993: Moderate 37 of 365 days1993: Unhealthy for Sensitive Groups 9 of 365 days1993: Unhealthy 1 of 365 days1993: Very Unhealthy 1 of 365 days1994: Good 299 of 365 days1994: Moderate 43 of 365 days1994: Unhealthy for Sensitive Groups 19 of 365 days1994: Unhealthy 3 of 365 days1994: Very Unhealthy 1 of 365 days1995: Good 297 of 365 days1995: Moderate 42 of 365 days1995: Unhealthy for Sensitive Groups 17 of 365 days1995: Unhealthy 7 of 365 days1995: Very Unhealthy 2 of 365 days19951996: Good 314 of 366 days1996: Moderate 34 of 366 days1996: Unhealthy for Sensitive Groups 13 of 366 days1996: Unhealthy 3 of 366 days1996: Very Unhealthy 2 of 366 days1997: Good 310 of 365 days1997: Moderate 38 of 365 days1997: Unhealthy for Sensitive Groups 15 of 365 days1997: Unhealthy 2 of 365 days1998: Good 282 of 365 days1998: Moderate 54 of 365 days1998: Unhealthy for Sensitive Groups 24 of 365 days1998: Unhealthy 5 of 365 days1999: Good 133 of 364 days1999: Moderate 195 of 364 days1999: Unhealthy for Sensitive Groups 26 of 364 days1999: Unhealthy 10 of 364 days2000: Good 133 of 366 days2000: Moderate 220 of 366 days2000: Unhealthy for Sensitive Groups 10 of 366 days2000: Unhealthy 3 of 366 days20002001: Good 124 of 365 days2001: Moderate 212 of 365 days2001: Unhealthy for Sensitive Groups 26 of 365 days2001: Unhealthy 3 of 365 days2002: Good 128 of 365 days2002: Moderate 208 of 365 days2002: Unhealthy for Sensitive Groups 22 of 365 days2002: Unhealthy 7 of 365 days2003: Good 135 of 365 days2003: Moderate 210 of 365 days2003: Unhealthy for Sensitive Groups 15 of 365 days2003: Unhealthy 4 of 365 days2003: Very Unhealthy 1 of 365 days2004: Good 169 of 366 days2004: Moderate 189 of 366 days2004: Unhealthy for Sensitive Groups 8 of 366 days2005: Good 152 of 365 days2005: Moderate 179 of 365 days2005: Unhealthy for Sensitive Groups 27 of 365 days2005: Unhealthy 7 of 365 days20052006: Good 223 of 365 days2006: Moderate 128 of 365 days2006: Unhealthy for Sensitive Groups 11 of 365 days2006: Unhealthy 3 of 365 days2007: Good 197 of 323 days2007: Moderate 103 of 323 days2007: Unhealthy for Sensitive Groups 18 of 323 days2007: Unhealthy 5 of 323 days2008: Good 172 of 360 days2008: Moderate 186 of 360 days2008: Unhealthy for Sensitive Groups 2 of 360 days2009: Good 247 of 365 days2009: Moderate 114 of 365 days2009: Unhealthy for Sensitive Groups 4 of 365 days2010: Good 274 of 365 days2010: Moderate 87 of 365 days2010: Unhealthy for Sensitive Groups 4 of 365 days20102011: Good 204 of 365 days2011: Moderate 155 of 365 days2011: Unhealthy for Sensitive Groups 6 of 365 days2012: Good 180 of 366 days2012: Moderate 165 of 366 days2012: Unhealthy for Sensitive Groups 20 of 366 days2012: Unhealthy 1 of 366 days2013: Good 200 of 365 days2013: Moderate 161 of 365 days2013: Unhealthy for Sensitive Groups 4 of 365 days2014: Good 174 of 365 days2014: Moderate 188 of 365 days2014: Unhealthy for Sensitive Groups 3 of 365 days2015: Good 202 of 365 days2015: Moderate 160 of 365 days2015: Unhealthy for Sensitive Groups 2 of 365 days2015: Unhealthy 1 of 365 days20152016: Good 212 of 366 days2016: Moderate 146 of 366 days2016: Unhealthy for Sensitive Groups 8 of 366 days2017: Good 228 of 365 days2017: Moderate 137 of 365 days2018: Good 244 of 365 days2018: Moderate 117 of 365 days2018: Unhealthy for Sensitive Groups 4 of 365 days2019: Good 261 of 365 days2019: Moderate 104 of 365 days2020: Good 267 of 365 days2020: Moderate 90 of 365 days2020: Unhealthy for Sensitive Groups 7 of 365 days2020: Unhealthy 1 of 365 days20202021: Good 189 of 365 days2021: Moderate 173 of 365 days2021: Unhealthy for Sensitive Groups 3 of 365 days2022: Good 209 of 365 days2022: Moderate 152 of 365 days2022: Unhealthy for Sensitive Groups 4 of 365 days2023: Good 188 of 365 days2023: Moderate 165 of 365 days2023: Unhealthy for Sensitive Groups 9 of 365 days2023: Unhealthy 2 of 365 days2023: Very Unhealthy 1 of 365 days2024: Good 180 of 366 days2024: Moderate 185 of 366 days2024: Unhealthy for Sensitive Groups 1 of 366 days2025: Good 153 of 365 days2025: Moderate 203 of 365 days2025: Unhealthy for Sensitive Groups 7 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 1001981: 90th percentile AQI 841982: 90th percentile AQI 901983: 90th percentile AQI 1051984: 90th percentile AQI 901985: 90th percentile AQI 841986: 90th percentile AQI 841987: 90th percentile AQI 1081988: 90th percentile AQI 1471989: 90th percentile AQI 1051990: 90th percentile AQI 931991: 90th percentile AQI 1011992: 90th percentile AQI 641993: 90th percentile AQI 581994: 90th percentile AQI 801995: 90th percentile AQI 841996: 90th percentile AQI 741997: 90th percentile AQI 671998: 90th percentile AQI 901999: 90th percentile AQI 1002000: 90th percentile AQI 852001: 90th percentile AQI 932002: 90th percentile AQI 952003: 90th percentile AQI 902004: 90th percentile AQI 802005: 90th percentile AQI 972006: 90th percentile AQI 762007: 90th percentile AQI 902008: 90th percentile AQI 772009: 90th percentile AQI 692010: 90th percentile AQI 672011: 90th percentile AQI 682012: 90th percentile AQI 842013: 90th percentile AQI 682014: 90th percentile AQI 662015: 90th percentile AQI 672016: 90th percentile AQI 682017: 90th percentile AQI 642018: 90th percentile AQI 642019: 90th percentile AQI 592020: 90th percentile AQI 622021: 90th percentile AQI 712022: 90th percentile AQI 682023: 90th percentile AQI 802024: 90th percentile AQI 682025: 90th percentile AQI 721980: Median AQI 381981: Median AQI 341982: Median AQI 331983: Median AQI 311984: Median AQI 311985: Median AQI 311986: Median AQI 311987: Median AQI 311988: Median AQI 321989: Median AQI 351990: Median AQI 311991: Median AQI 311992: Median AQI 301993: Median AQI 281994: Median AQI 311995: Median AQI 291996: Median AQI 281997: Median AQI 261998: Median AQI 311999: Median AQI 572000: Median AQI 572001: Median AQI 582002: Median AQI 562003: Median AQI 562004: Median AQI 522005: Median AQI 552006: Median AQI 442007: Median AQI 442008: Median AQI 522009: Median AQI 412010: Median AQI 382011: Median AQI 472012: Median AQI 512013: Median AQI 482014: Median AQI 512015: Median AQI 472016: Median AQI 462017: Median AQI 442018: Median AQI 432019: Median AQI 402020: Median AQI 392021: Median AQI 492022: Median AQI 472023: Median AQI 492024: Median AQI 512025: Median AQI 521980198519901995200020052010201520202025
  • 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
Fine particles (PM2.5)30684%
Ozone5515%
Nitrogen dioxide (NO₂)31%
Coarse particles (PM10)1<1%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536515320372005272163PM2.5
202436618018510005168112PM2.5
202336518816592104980220PM2.5
202236520915240004768136PM2.5
202136518917330004971143PM2.5
20203652679071003962154Ozone
20193652611040000405990PM2.5
201836524411740004364115PM2.5
201736522813700004464100PM2.5
201636621214680004668129PM2.5
201536520216021004767154PM2.5
201436517418830005166121PM2.5
201336520016140004868138PM2.5
2012366180165201005184159PM2.5
201136520415560004768140PM2.5
20103652748740003867126Ozone
200936524711440004169140Ozone
200836017218620005277143PM2.5
2007323197103185004490164Ozone
2006365223128113004476197PM2.5
2005365152179277005597172PM2.5
200436616918980005280140PM2.5
2003365135210154105690201PM2.5
2002365128208227005695185PM2.5
2001365124212263005893169PM2.5
2000366133220103005785192PM2.5
199936413319526100057100197PM2.5
199836528254245003190182Ozone
199736531038152002667159Ozone
199636631434133202874213Ozone
199536529742177202984229Ozone
199436529943193103180215Ozone
19933653173791102858202Ozone
199236630845103003064166Ozone
19913652903528111031101217Ozone
199036529441227103193204Ozone
19893652705426132035105222Ozone
198836627932222310032147230Ozone
19873652774922134031108218Ozone
198636530141167003184179Ozone
198536530243163103184205Ozone
198435429237169003190185Ozone
1983359278422793031105217Ozone
198236528849217003390182Ozone
198136429743194103484202Ozone
19803662656720140038100192Ozone

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 Michigan with a similar median AQI in 2025

All monitored counties in Michigan

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