Bad Air Days in Clackamas County, Oregon: 6 a Year
6 bad air days a year
More bad air days than three quarters of monitored counties. Ranked 183 of 996 monitored counties, where 1 is worst.
What makes them bad: a mix of particles and ozone (45% particle days).
When the bad days come in Clackamas
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Most bad days here fall in August and September. Averaged over 2016 to 2025.
What actually helps here
- Ozone drives many bad days here. Purifiers and filters do not remove ozone, so do not buy one for that. Ozone peaks on hot afternoons: exercise outside in the morning.
The record for Clackamas
In 2000 to 2009 this county averaged 4 bad days a year; in 2016 to 2025, 6. Not much has changed. The worst recent year was 2017, with 12 bad days on 216 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2020-09-12 | 481 | PM2.5 |
| 2020-09-13 | 432 | PM2.5 |
| 2020-09-14 | 403 | PM2.5 |
| 2020-09-15 | 318 | PM2.5 |
| 2017-08-03 | 212 | Ozone |
The air on a normal day
Across 2,951 monitored days from 2016 to 2025, the air in Clackamas County rated Good on 87% of them, more often than the 72% typical of monitored counties, and Moderate on 12%. The median day sat at AQI 32; one day in ten went above 55.
The pollutant setting the AQI on an ordinary day here:
- fine particles (PM2.5)56%1,660 days
- ozone44%1,291 days
Clackamas County by year
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 363 | 318 | 43 | 2 | 0 | 31 | 119 |
| 2024 | 365 | 325 | 34 | 6 | 0 | 30 | 127 |
| 2023 | 365 | 304 | 57 | 4 | 0 | 34 | 125 |
| 2022 | 364 | 286 | 73 | 5 | 2 | 33 | 168 |
| 2021 | 354 | 320 | 33 | 1 | 1 | 31 | 161 |
| 2020 | 272 | 238 | 25 | 9 | 6 | 33 | 481 |
| 2019 | 225 | 214 | 10 | 1 | 0 | 31 | 101 |
| 2018 | 212 | 174 | 32 | 6 | 1 | 37 | 170 |
| 2017 | 216 | 178 | 26 | 12 | 3 | 33 | 212 |
| 2016 | 215 | 202 | 12 | 1 | 0 | 29 | 108 |
| 2015 | 222 | 190 | 28 | 4 | 2 | 35 | 180 |
| 2014 | 219 | 189 | 27 | 3 | 1 | 34 | 153 |
| 2013 | 215 | 199 | 16 | 0 | 0 | 34 | 84 |
| 2012 | 225 | 194 | 30 | 1 | 0 | 32 | 108 |
| 2011 | 221 | 208 | 12 | 1 | 0 | 30 | 117 |
| 2010 | 229 | 217 | 10 | 2 | 1 | 27 | 172 |
*2025 may be a partial year in EPA's file.
Nearby counties on file
- Klamath County20/yr
- Josephine County17/yr
- Jackson County16/yr
- Lane County16/yr
- Deschutes County14/yr
- Lake County10/yr
- Harney County7/yr
- Crook County7/yr
How this is counted
A bad air day is a day the county's daily AQI from EPA AirData went above 100, the level where EPA tells children, older adults and people with asthma or heart disease to cut back outdoors. Monitors do not run every day, so yearly counts are scaled to 365 days. This is the record, not today's air: for that, check AirNow. More on the method in how the county numbers are made, on the AQI 100 line in what counts as a bad air day, and on why a purifier does not touch ozone in smoke vs ozone.