BadAirDays

Bad Air Days in Crook County, Oregon: 7 a Year

7 bad air days a year

More bad air days than three quarters of monitored counties. Ranked 162 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly particles: smoke and dust (100% particle days).

The bad-air season here

  1. J
  2. F
  3. M
  4. A
  5. M
  6. J
  7. J
  8. A
  9. S
  10. O
  11. N
  12. D

Most bad days here fall in September and August. Averaged over 2016 to 2025.

What to buy, and what not to

Better or worse than it was

In 2000 to 2009 this county averaged 9 bad days a year; in 2016 to 2025, 7. The air has improved. The worst recent year was 2017, with 16 bad days on 357 monitored days.

DateAQIMain pollutant
2020-09-121033PM2.5
2020-09-13443PM2.5
2020-09-15441PM2.5
2020-09-17279PM2.5
2020-09-16256PM2.5

The air on a normal day

Across 3,618 monitored days from 2016 to 2025, the air in Crook County rated Good on 73% of them, close to the 72% typical of monitored counties, and Moderate on 25%. The median day sat at AQI 29; one day in ten went above 65.

The pollutant setting the AQI on an ordinary day here:

Year by year

YearDays monitoredGoodModerateOver 100Over 150Median AQIHighest AQI
2025*365266972028144
2024366282768324173
20233652678612633171
2022359288692024128
2021365281759328190
20203652619777281033
2019365266981030103
20183632511057234169
201735722911216835224
2016348261861026115
20153622521028232170
201436525010510631180
201336519815413247151
20123602391192033105
20113562411096028143
2010359278801027102

*2025 may be a partial year in EPA's file.

Elsewhere in Oregon

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.