Stanislaus, California Air Quality
Stanislaus County, California (CA)
↓ Improvingover 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). This area has seen measurable air quality improvement over the 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 | 54 | 93 | 150 | 166 | 176 | 23 | Ozone |
| 2022 | 57 | 95 | 166 | 108 | 234 | 23 | PM2.5 |
| 2021 | 61 | 105 | 172 | 84 | 234 | 47 | PM2.5 |
| 2020 | 60 | 102 | 195 | 131 | 198 | 37 | PM2.5 |
| 2019 | 52 | 92 | 177 | 168 | 174 | 23 | Ozone |
| 2018 | 59 | 108 | 265 | 109 | 209 | 47 | PM2.5 |
| 2017 | 61 | 112 | 185 | 127 | 175 | 63 | Ozone |
| 2016 | 59 | 103 | 164 | 102 | 221 | 43 | PM2.5 |
| 2015 | 62 | 112 | 187 | 92 | 225 | 48 | PM2.5 |
| 2014 | 60 | 114 | 164 | 112 | 194 | 59 | Ozone |
What This Means for Stanislaus County Residents
Stanislaus, California has received an Air Quality Grade of D (46/100) based on a decade of EPA monitoring data. The current median AQI of 54 falls in the "Moderate" range.
Encouragingly, air quality here has been improving, with the median AQI dropping by 6 points over the monitoring period. This trend suggests continued investment in emission controls and cleaner energy.
The primary pollutant affecting this area is Fine Particulate Matter (PM2.5). Over the past 5 years, this area has averaged 31 unhealthy air quality days per year — days when sensitive groups (children, elderly, those with respiratory conditions) should limit outdoor activity.