EnviroNearby

Sherburne County, Minnesota air quality history

Daily Air Quality Index summaries from EPA monitors in Sherburne, Minnesota, 1980–1998.

88%
Good days in 1987
23
Median daily AQI, 1987
0
Days above 100 in 1987
147
Days with an AQI in 1987 (of 365)

In 1987, EPA reported a daily Air Quality Index (AQI) for Sherburne, Minnesota on 147 days. 129 of those days (88%) were in the Good range, and the median daily AQI was 23. That median is lower than the typical monitored county in Minnesota (median 31.5 across 12 counties), and lower than the typical monitored U.S. county (42). The main pollutant was carbon monoxide (CO) on 147 days. Across the years with fuller monitoring, the share of Good days rose: an average of 76% in 1980–1982 versus 90% in 1985–1987.

EPA did not report an AQI for every day of 1987 here (147 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.

The most recent year with data for this county is 1998; EPA's files for 1999–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (1992, 1994, 1995, 1996, 1997, 1998…) 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 259 of 364 days1980: Moderate 96 of 364 days1980: Unhealthy for Sensitive Groups 7 of 364 days1980: Unhealthy 2 of 364 days19801981: Good 276 of 360 days1981: Moderate 79 of 360 days1981: Unhealthy for Sensitive Groups 3 of 360 days1981: Very Unhealthy 2 of 360 days1982: Good 287 of 358 days1982: Moderate 68 of 358 days1982: Unhealthy for Sensitive Groups 3 of 358 days19821983: Good 263 of 282 days1983: Moderate 19 of 282 days1984: Good 261 of 304 days1984: Moderate 43 of 304 days19841985: Good 312 of 352 days1985: Moderate 36 of 352 days1985: Unhealthy for Sensitive Groups 3 of 352 days1985: Unhealthy 1 of 352 days1986: Good 338 of 363 days1986: Moderate 25 of 363 days19861987: Good 129 of 147 days1987: Moderate 18 of 147 days1988: Good 31 of 31 days19881989: Good 59 of 59 days1990: Good 60 of 61 days1990: Moderate 1 of 61 days19901991: Good 60 of 60 days1992: Good 65 of 65 days19921994: Good 64 of 64 days1995: Good 61 of 61 days19951996: Good 60 of 61 days1996: Moderate 1 of 61 days1997: Good 42 of 42 days19971998: Good 41 of 41 days1998
  • 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 701981: 90th percentile AQI 661982: 90th percentile AQI 641983: 90th percentile AQI 481984: 90th percentile AQI 561985: 90th percentile AQI 511986: 90th percentile AQI 471987: 90th percentile AQI 561988: 90th percentile AQI 271989: 90th percentile AQI 311990: 90th percentile AQI 271991: 90th percentile AQI 211992: 90th percentile AQI 211994: 90th percentile AQI 191995: 90th percentile AQI 291996: 90th percentile AQI 191997: 90th percentile AQI 201998: 90th percentile AQI 261980: Median AQI 411981: Median AQI 381982: Median AQI 361983: Median AQI 241984: Median AQI 301985: Median AQI 271986: Median AQI 231987: Median AQI 231988: Median AQI 191989: Median AQI 161990: Median AQI 131991: Median AQI 121992: Median AQI 91994: Median AQI 101995: Median AQI 121996: Median AQI 91997: Median AQI 101998: Median AQI 161980198219841986198819901992199519971998
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 1987

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
Carbon monoxide (CO)147100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
1998414100000162638PM10
1997424200000102030PM10
199661601000091956PM10
1995616100000122940PM10
1994646400000101931PM10
199265650000092134PM10
1991606000000122134PM10
1990616010000132774PM10
1989595900000163141PM10
1988313100000192739PM10
1987147129180000235682CO
1986363338250000234798CO
19853523123631002751151CO
1984304261430000305685CO
1983282263190000244898CO
19823582876830003664116CO
19813602767930203866208CO
19803642599672004170179CO

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.

All monitored counties in Minnesota

Source: U.S. EPA AirData, “Annual AQI by County” files for 1980–1998 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem