EnviroNearby

Clackamas County, Oregon air quality history

Daily Air Quality Index summaries from EPA monitors in Clackamas, Oregon, 1980–2025.

88%
Good days in 2025
31
Median daily AQI, 2025
2
Days above 100 in 2025
363
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Clackamas, Oregon on 363 days. 318 of those days (88%) were in the Good range, and the median daily AQI was 31. That median is about the same as the typical monitored county in Oregon (median 29 across 21 counties), and lower than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 232 days. Across the years with fuller monitoring, the share of Good days fell: an average of 93% in 1980–1982 versus 87% 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 349 of 366 days1980: Moderate 15 of 366 days1980: Unhealthy for Sensitive Groups 2 of 366 days19801981: Good 331 of 363 days1981: Moderate 13 of 363 days1981: Unhealthy for Sensitive Groups 13 of 363 days1981: Unhealthy 3 of 363 days1981: Very Unhealthy 3 of 363 days1982: Good 340 of 365 days1982: Moderate 16 of 365 days1982: Unhealthy for Sensitive Groups 7 of 365 days1982: Unhealthy 2 of 365 days1983: Good 348 of 362 days1983: Moderate 10 of 362 days1983: Unhealthy for Sensitive Groups 2 of 362 days1983: Unhealthy 2 of 362 days1984: Good 350 of 365 days1984: Moderate 11 of 365 days1984: Unhealthy for Sensitive Groups 2 of 365 days1984: Unhealthy 2 of 365 days1985: Good 329 of 365 days1985: Moderate 22 of 365 days1985: Unhealthy for Sensitive Groups 9 of 365 days1985: Unhealthy 4 of 365 days1985: Very Unhealthy 1 of 365 days19851986: Good 272 of 302 days1986: Moderate 13 of 302 days1986: Unhealthy for Sensitive Groups 10 of 302 days1986: Unhealthy 5 of 302 days1986: Very Unhealthy 2 of 302 days1987: Good 158 of 202 days1987: Moderate 29 of 202 days1987: Unhealthy for Sensitive Groups 12 of 202 days1987: Unhealthy 2 of 202 days1987: Very Unhealthy 1 of 202 days1988: Good 191 of 226 days1988: Moderate 25 of 226 days1988: Unhealthy for Sensitive Groups 7 of 226 days1988: Unhealthy 2 of 226 days1988: Very Unhealthy 1 of 226 days1989: Good 215 of 232 days1989: Moderate 15 of 232 days1989: Unhealthy for Sensitive Groups 2 of 232 days1990: Good 195 of 275 days1990: Moderate 66 of 275 days1990: Unhealthy for Sensitive Groups 6 of 275 days1990: Unhealthy 5 of 275 days1990: Very Unhealthy 3 of 275 days19901991: Good 184 of 260 days1991: Moderate 69 of 260 days1991: Unhealthy for Sensitive Groups 5 of 260 days1991: Unhealthy 2 of 260 days1992: Good 147 of 186 days1992: Moderate 27 of 186 days1992: Unhealthy for Sensitive Groups 7 of 186 days1992: Unhealthy 5 of 186 days1993: Good 179 of 188 days1993: Moderate 8 of 188 days1993: Unhealthy for Sensitive Groups 1 of 188 days1994: Good 159 of 188 days1994: Moderate 24 of 188 days1994: Unhealthy for Sensitive Groups 4 of 188 days1994: Unhealthy 1 of 188 days1995: Good 166 of 187 days1995: Moderate 15 of 187 days1995: Unhealthy for Sensitive Groups 5 of 187 days1995: Unhealthy 1 of 187 days19951996: Good 161 of 187 days1996: Moderate 9 of 187 days1996: Unhealthy for Sensitive Groups 12 of 187 days1996: Unhealthy 2 of 187 days1996: Very Unhealthy 3 of 187 days1997: Good 179 of 189 days1997: Moderate 8 of 189 days1997: Unhealthy for Sensitive Groups 2 of 189 days1998: Good 163 of 187 days1998: Moderate 15 of 187 days1998: Unhealthy for Sensitive Groups 6 of 187 days1998: Unhealthy 2 of 187 days1998: Very Unhealthy 1 of 187 days1999: Good 168 of 187 days1999: Moderate 14 of 187 days1999: Unhealthy for Sensitive Groups 5 of 187 days2000: Good 185 of 198 days2000: Moderate 12 of 198 days2000: Unhealthy for Sensitive Groups 1 of 198 days20002001: Good 206 of 220 days2001: Moderate 11 of 220 days2001: Unhealthy for Sensitive Groups 3 of 220 days2002: Good 210 of 224 days2002: Moderate 12 of 224 days2002: Unhealthy for Sensitive Groups 2 of 224 days2003: Good 196 of 223 days2003: Moderate 20 of 223 days2003: Unhealthy for Sensitive Groups 7 of 223 days2004: Good 259 of 359 days2004: Moderate 97 of 359 days2004: Unhealthy for Sensitive Groups 3 of 359 days2005: Good 271 of 313 days2005: Moderate 40 of 313 days2005: Unhealthy for Sensitive Groups 2 of 313 days20052006: Good 201 of 243 days2006: Moderate 37 of 243 days2006: Unhealthy for Sensitive Groups 4 of 243 days2006: Very Unhealthy 1 of 243 days2007: Good 209 of 222 days2007: Moderate 13 of 222 days2008: Good 206 of 221 days2008: Moderate 12 of 221 days2008: Unhealthy for Sensitive Groups 3 of 221 days2009: Good 190 of 225 days2009: Moderate 32 of 225 days2009: Unhealthy for Sensitive Groups 3 of 225 days2010: Good 217 of 229 days2010: Moderate 10 of 229 days2010: Unhealthy for Sensitive Groups 1 of 229 days2010: Unhealthy 1 of 229 days20102011: Good 208 of 221 days2011: Moderate 12 of 221 days2011: Unhealthy for Sensitive Groups 1 of 221 days2012: Good 194 of 225 days2012: Moderate 30 of 225 days2012: Unhealthy for Sensitive Groups 1 of 225 days2013: Good 199 of 215 days2013: Moderate 16 of 215 days2014: Good 189 of 219 days2014: Moderate 27 of 219 days2014: Unhealthy for Sensitive Groups 2 of 219 days2014: Unhealthy 1 of 219 days2015: Good 190 of 222 days2015: Moderate 28 of 222 days2015: Unhealthy for Sensitive Groups 2 of 222 days2015: Unhealthy 2 of 222 days20152016: Good 202 of 215 days2016: Moderate 12 of 215 days2016: Unhealthy for Sensitive Groups 1 of 215 days2017: Good 178 of 216 days2017: Moderate 26 of 216 days2017: Unhealthy for Sensitive Groups 9 of 216 days2017: Unhealthy 2 of 216 days2017: Very Unhealthy 1 of 216 days2018: Good 174 of 212 days2018: Moderate 32 of 212 days2018: Unhealthy for Sensitive Groups 5 of 212 days2018: Unhealthy 1 of 212 days2019: Good 214 of 225 days2019: Moderate 10 of 225 days2019: Unhealthy for Sensitive Groups 1 of 225 days2020: Good 238 of 272 days2020: Moderate 25 of 272 days2020: Unhealthy for Sensitive Groups 3 of 272 days2020: Unhealthy 2 of 272 days2020: Hazardous 4 of 272 days20202021: Good 320 of 354 days2021: Moderate 33 of 354 days2021: Unhealthy 1 of 354 days2022: Good 286 of 364 days2022: Moderate 73 of 364 days2022: Unhealthy for Sensitive Groups 3 of 364 days2022: Unhealthy 2 of 364 days2023: Good 304 of 365 days2023: Moderate 57 of 365 days2023: Unhealthy for Sensitive Groups 4 of 365 days2024: Good 325 of 365 days2024: Moderate 34 of 365 days2024: Unhealthy for Sensitive Groups 6 of 365 days2025: Good 318 of 363 days2025: Moderate 43 of 363 days2025: Unhealthy for Sensitive Groups 2 of 363 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 411981: 90th percentile AQI 481982: 90th percentile AQI 461983: 90th percentile AQI 381984: 90th percentile AQI 431985: 90th percentile AQI 501986: 90th percentile AQI 501987: 90th percentile AQI 901988: 90th percentile AQI 641989: 90th percentile AQI 481990: 90th percentile AQI 741991: 90th percentile AQI 741992: 90th percentile AQI 711993: 90th percentile AQI 441994: 90th percentile AQI 641995: 90th percentile AQI 541996: 90th percentile AQI 901997: 90th percentile AQI 471998: 90th percentile AQI 671999: 90th percentile AQI 512000: 90th percentile AQI 472001: 90th percentile AQI 462002: 90th percentile AQI 442003: 90th percentile AQI 582004: 90th percentile AQI 632005: 90th percentile AQI 542006: 90th percentile AQI 672007: 90th percentile AQI 462008: 90th percentile AQI 452009: 90th percentile AQI 572010: 90th percentile AQI 432011: 90th percentile AQI 442012: 90th percentile AQI 582013: 90th percentile AQI 492014: 90th percentile AQI 542015: 90th percentile AQI 572016: 90th percentile AQI 442017: 90th percentile AQI 712018: 90th percentile AQI 712019: 90th percentile AQI 442020: 90th percentile AQI 532021: 90th percentile AQI 502022: 90th percentile AQI 612023: 90th percentile AQI 542024: 90th percentile AQI 512025: 90th percentile AQI 531980: Median AQI 261981: Median AQI 291982: Median AQI 281983: Median AQI 271984: Median AQI 291985: Median AQI 301986: Median AQI 311987: Median AQI 371988: Median AQI 331989: Median AQI 321990: Median AQI 371991: Median AQI 411992: Median AQI 341993: Median AQI 291994: Median AQI 361995: Median AQI 321996: Median AQI 321997: Median AQI 311998: Median AQI 311999: Median AQI 332000: Median AQI 292001: Median AQI 282002: Median AQI 292003: Median AQI 332004: Median AQI 372005: Median AQI 322006: Median AQI 332007: Median AQI 302008: Median AQI 312009: Median AQI 322010: Median AQI 272011: Median AQI 302012: Median AQI 322013: Median AQI 342014: Median AQI 342015: Median AQI 352016: Median AQI 292017: Median AQI 332018: Median AQI 372019: Median AQI 312020: Median AQI 332021: Median AQI 312022: Median AQI 332023: Median AQI 342024: Median AQI 302025: Median AQI 311980198519901995200020052010201520202025
  • 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)23264%
Ozone13136%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253633184320003153119PM2.5
20243653253460003051127PM2.5
20233653045740003454125PM2.5
20223642867332003361168PM2.5
20213543203301003150161PM2.5
20202722382532043353481PM2.5
20192252141010003144101Ozone
20182121743251003771170PM2.5
20172161782692103371212Ozone
20162152021210002944108Ozone
20152221902822003557180PM2.5
20142191892721003454153PM2.5
2013215199160000344984PM2.5
20122251943010003258108Ozone
20112212081210003044117Ozone
20102292171011002743172Ozone
20092251903230003257133PM2.5
20082212061230003145147PM2.5
20072222091300003046100PM2.5
20062432013740103367201PM2.5
20053132714020003254129PM2.5
20043592599730003763147PM2.5
20032231962070003358147Ozone
20022242101220002944150Ozone
20012202061130002846133Ozone
20001981851210002947101Ozone
19991871681450003351133Ozone
19981871631562103167212Ozone
1997189179820003147140Ozone
19961871619122303290216Ozone
19951871661551003254166Ozone
19941881592441003664154Ozone
1993188179810002944108Ozone
19921861472775003471182Ozone
19912601846952004174187Ozone
19902751956665303774208Ozone
19892322151520003248133Ozone
19882261912572103364227Ozone
198720215829122103790204Ozone
198630227213105203150212Ozone
19853653292294103050206Ozone
19843653501122002943200Ozone
19833623481022002738179Ozone
19823653401672002846179Ozone
198136333113133302948258Ozone
19803663491520002641143Ozone

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 Oregon with a similar median AQI in 2025

All monitored counties in Oregon

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