Siskiyou, California Air Quality
Siskiyou County, California (CA)
↑ Worseningover 10 years
10-Year AQI Trend
The solid line shows the median AQI each year. The dashed line shows the 90th percentile (worst 10% of days). Air quality in this area has been declining over the past decade.
Air Quality Day Breakdown
Number of days per year in each EPA AQI category. Green = Good (AQI 0-50), Yellow = Moderate (51-100), Orange = Unhealthy for Sensitive Groups (101-150), Red = Unhealthy or worse (151+).
Year-by-Year Data
| Year | Median AQI | 90th Pct | Max AQI | Good Days | Moderate | Unhealthy+ | Pollutant |
|---|---|---|---|---|---|---|---|
| 2023 | 43 | 64 | 320 | 270 | 78 | 17 | Ozone |
| 2022 | 41 | 62 | 454 | 269 | 86 | 7 | Ozone |
| 2021 | 43 | 86 | 210 | 237 | 96 | 31 | PM2.5 |
| 2020 | 39 | 66 | 468 | 272 | 71 | 23 | Ozone |
| 2019 | 38 | 54 | 164 | 302 | 59 | 4 | Ozone |
| 2018 | 42 | 119 | 219 | 247 | 78 | 40 | Ozone |
| 2017 | 28 | 57 | 167 | 198 | 23 | 4 | Ozone |
| 2016 | 27 | 44 | 93 | 351 | 11 | 0 | Ozone |
| 2015 | 36 | 49 | 139 | 330 | 28 | 4 | Ozone |
| 2014 | 37 | 50 | 162 | 330 | 31 | 2 | Ozone |
What This Means for Siskiyou County Residents
Siskiyou, California has received an Air Quality Grade of D (49/100) based on a decade of EPA monitoring data. The current median AQI of 43 falls in the "Good" range.
Concerning trends show air quality has been declining, with the median AQI rising by 6 points over the monitoring period. This could be driven by increased development, wildfire smoke, or industrial activity.
The primary pollutant affecting this area is Ground-Level Ozone. Over the past 5 years, this area has averaged 16 unhealthy air quality days per year — days when sensitive groups (children, elderly, those with respiratory conditions) should limit outdoor activity.