EnviroNearby

Lake County, Minnesota air quality history

Daily Air Quality Index summaries from EPA monitors in Lake, Minnesota, 1980–2025.

86%
Good days in 2025
31
Median daily AQI, 2025
15
Days above 100 in 2025
361
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Lake, Minnesota on 361 days. 310 of those days (86%) were in the Good range, and the median daily AQI was 31. That median is lower than the typical monitored county in Minnesota (median 37 across 21 counties), and lower than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 206 days. Across the years with fuller monitoring, the share of Good days fell: an average of 97% in 1980–1982 versus 84% in 2023–2025.

Years with fewer than 120 monitored days (1988, 1991) are shown in the table but left out of comparisons and trend statements.

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 189 of 198 days1980: Moderate 7 of 198 days1980: Unhealthy for Sensitive Groups 1 of 198 days1980: Unhealthy 1 of 198 days19801981: Good 146 of 151 days1981: Moderate 5 of 151 days1982: Good 159 of 162 days1982: Moderate 3 of 162 days1984: Good 164 of 168 days1984: Moderate 4 of 168 days1985: Good 222 of 238 days1985: Moderate 15 of 238 days1985: Unhealthy for Sensitive Groups 1 of 238 days1986: Good 206 of 212 days1986: Moderate 6 of 212 days19861987: Good 122 of 138 days1987: Moderate 14 of 138 days1987: Unhealthy for Sensitive Groups 2 of 138 days1988: Good 83 of 95 days1988: Moderate 7 of 95 days1988: Unhealthy for Sensitive Groups 3 of 95 days1988: Unhealthy 2 of 95 days1989: Good 107 of 141 days1989: Moderate 31 of 141 days1989: Unhealthy for Sensitive Groups 3 of 141 days1990: Good 187 of 187 days1991: Good 70 of 76 days1991: Moderate 6 of 76 days19911992: Good 251 of 273 days1992: Moderate 22 of 273 days1993: Good 185 of 199 days1993: Moderate 14 of 199 days1994: Good 304 of 348 days1994: Moderate 41 of 348 days1994: Unhealthy for Sensitive Groups 3 of 348 days1995: Good 328 of 356 days1995: Moderate 27 of 356 days1995: Unhealthy for Sensitive Groups 1 of 356 days1996: Good 323 of 354 days1996: Moderate 31 of 354 days19961997: Good 333 of 361 days1997: Moderate 27 of 361 days1997: Unhealthy for Sensitive Groups 1 of 361 days1998: Good 296 of 321 days1998: Moderate 24 of 321 days1998: Unhealthy for Sensitive Groups 1 of 321 days1999: Good 322 of 348 days1999: Moderate 24 of 348 days1999: Unhealthy for Sensitive Groups 2 of 348 days2000: Good 208 of 230 days2000: Moderate 21 of 230 days2000: Unhealthy for Sensitive Groups 1 of 230 days2001: Good 215 of 229 days2001: Moderate 13 of 229 days2001: Unhealthy for Sensitive Groups 1 of 229 days20012002: Good 203 of 221 days2002: Moderate 15 of 221 days2002: Unhealthy for Sensitive Groups 3 of 221 days2003: Good 194 of 219 days2003: Moderate 25 of 219 days2004: Good 217 of 226 days2004: Moderate 9 of 226 days2005: Good 265 of 302 days2005: Moderate 36 of 302 days2005: Unhealthy for Sensitive Groups 1 of 302 days2006: Good 312 of 360 days2006: Moderate 47 of 360 days2006: Unhealthy for Sensitive Groups 1 of 360 days20062007: Good 291 of 354 days2007: Moderate 60 of 354 days2007: Unhealthy for Sensitive Groups 3 of 354 days2008: Good 298 of 361 days2008: Moderate 63 of 361 days2009: Good 272 of 352 days2009: Moderate 80 of 352 days2010: Good 299 of 350 days2010: Moderate 50 of 350 days2010: Unhealthy for Sensitive Groups 1 of 350 days2011: Good 282 of 356 days2011: Moderate 66 of 356 days2011: Unhealthy for Sensitive Groups 7 of 356 days2011: Unhealthy 1 of 356 days20112012: Good 300 of 365 days2012: Moderate 64 of 365 days2012: Unhealthy for Sensitive Groups 1 of 365 days2013: Good 311 of 365 days2013: Moderate 54 of 365 days2014: Good 310 of 365 days2014: Moderate 55 of 365 days2015: Good 332 of 365 days2015: Moderate 32 of 365 days2015: Unhealthy for Sensitive Groups 1 of 365 days2016: Good 347 of 366 days2016: Moderate 19 of 366 days20162017: Good 330 of 365 days2017: Moderate 35 of 365 days2018: Good 310 of 365 days2018: Moderate 55 of 365 days2019: Good 333 of 363 days2019: Moderate 30 of 363 days2020: Good 344 of 365 days2020: Moderate 21 of 365 days2021: Good 315 of 362 days2021: Moderate 43 of 362 days2021: Unhealthy for Sensitive Groups 3 of 362 days2021: Unhealthy 1 of 362 days20212022: Good 342 of 357 days2022: Moderate 15 of 357 days2023: Good 282 of 365 days2023: Moderate 81 of 365 days2023: Unhealthy for Sensitive Groups 2 of 365 days2024: Good 330 of 366 days2024: Moderate 35 of 366 days2024: Unhealthy for Sensitive Groups 1 of 366 days2025: Good 310 of 361 days2025: Moderate 36 of 361 days2025: Unhealthy for Sensitive Groups 8 of 361 days2025: Unhealthy 7 of 361 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 year0501001980: 90th percentile AQI 441981: 90th percentile AQI 441982: 90th percentile AQI 401984: 90th percentile AQI 421985: 90th percentile AQI 491986: 90th percentile AQI 441987: 90th percentile AQI 511988: 90th percentile AQI 671989: 90th percentile AQI 771990: 90th percentile AQI 221991: 90th percentile AQI 491992: 90th percentile AQI 471993: 90th percentile AQI 401994: 90th percentile AQI 541995: 90th percentile AQI 471996: 90th percentile AQI 491997: 90th percentile AQI 461998: 90th percentile AQI 491999: 90th percentile AQI 482000: 90th percentile AQI 502001: 90th percentile AQI 462002: 90th percentile AQI 502003: 90th percentile AQI 512004: 90th percentile AQI 462005: 90th percentile AQI 522006: 90th percentile AQI 542007: 90th percentile AQI 552008: 90th percentile AQI 542009: 90th percentile AQI 582010: 90th percentile AQI 542011: 90th percentile AQI 612012: 90th percentile AQI 562013: 90th percentile AQI 542014: 90th percentile AQI 542015: 90th percentile AQI 502016: 90th percentile AQI 432017: 90th percentile AQI 502018: 90th percentile AQI 562019: 90th percentile AQI 482020: 90th percentile AQI 462021: 90th percentile AQI 542022: 90th percentile AQI 442023: 90th percentile AQI 612024: 90th percentile AQI 492025: 90th percentile AQI 601980: Median AQI 311981: Median AQI 311982: Median AQI 281984: Median AQI 311985: Median AQI 371986: Median AQI 351987: Median AQI 391988: Median AQI 351989: Median AQI 411990: Median AQI 111991: Median AQI 181992: Median AQI 191993: Median AQI 241994: Median AQI 331995: Median AQI 311996: Median AQI 351997: Median AQI 351998: Median AQI 341999: Median AQI 322000: Median AQI 302001: Median AQI 312002: Median AQI 352003: Median AQI 352004: Median AQI 312005: Median AQI 302006: Median AQI 272007: Median AQI 302008: Median AQI 312009: Median AQI 362010: Median AQI 302011: Median AQI 342012: Median AQI 332013: Median AQI 332014: Median AQI 312015: Median AQI 322016: Median AQI 242017: Median AQI 302018: Median AQI 342019: Median AQI 312020: Median AQI 342021: Median AQI 312022: Median AQI 312023: Median AQI 362024: Median AQI 322025: Median AQI 311980198619911996200120062011201620212025
  • 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)20657%
Ozone15543%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253613103687003160191PM2.5
20243663303510003249110PM2.5
20233652828120003661114PM2.5
2022357342150000314478Ozone
20213623154331003154160Ozone
2020365344210000344671PM2.5
2019363333300000314883PM2.5
2018365310550000345696Ozone
2017365330350000305085Ozone
2016366347190000244386Ozone
20153653323210003250110PM2.5
2014365310550000315493PM2.5
2013365311540000335486Ozone
20123653006410003356108PM2.5
20113562826671003461170PM2.5
20103502995010003054123PM2.5
2009352272800000365884PM2.5
2008361298630000315493PM2.5
20073542916030003055119PM2.5
20063603124710002754105PM2.5
20053022653610003052108Ozone
200422621790000314671Ozone
2003219194250000355184Ozone
20022212031530003550112Ozone
20012292151310003146126Ozone
20002302082110003050112Ozone
19993483222420003248119Ozone
19983212962410003449115Ozone
19973613332710003546122Ozone
1996354323310000354997Ozone
19953563282710003147101Ozone
19943483044130003354140Ozone
1993199185140000244074PM2.5
1992273251220000194780NO2
1991767060000184958PM10
199018718700000112242NO2
19891411073130004177119Ozone
19889583732003567172Ozone
19871381221420003951133Ozone
198621220660000354471Ozone
19852382221510003749133Ozone
198416816440000314274Ozone
198216215930000284067Ozone
198115114650000314493Ozone
1980198189711003144192Ozone

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 Minnesota with a similar median AQI in 2025

All monitored counties in Minnesota

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