San Diego, California Air Quality
San Diego County, California (CA)
→ Stableover 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 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 | 67 | 101 | 150 | 61 | 260 | 44 | Ozone |
| 2022 | 63 | 97 | 156 | 42 | 297 | 26 | PM2.5 |
| 2021 | 67 | 90 | 133 | 52 | 297 | 16 | PM2.5 |
| 2020 | 74 | 108 | 192 | 33 | 284 | 49 | PM2.5 |
| 2019 | 66 | 93 | 169 | 38 | 302 | 25 | PM2.5 |
| 2018 | 67 | 100 | 143 | 28 | 302 | 35 | PM2.5 |
| 2017 | 68 | 112 | 174 | 41 | 262 | 62 | Ozone |
| 2016 | 68 | 105 | 164 | 30 | 294 | 42 | PM2.5 |
| 2015 | 65 | 102 | 156 | 46 | 278 | 41 | PM2.5 |
| 2014 | 65 | 101 | 170 | 48 | 278 | 39 | PM2.5 |
What This Means for San Diego County Residents
San Diego, California has received an Air Quality Grade of D (36/100) based on a decade of monitoring data from the EPA's air quality monitoring program. The current median AQI of 67 falls in the "Moderate" range.
The primary pollutant affecting this area is Fine Particulate Matter (PM2.5). Over the past 5 years, this area has averaged 32 unhealthy air quality days per year — days when sensitive groups (children, elderly, those with respiratory conditions) should limit outdoor activity. The American Lung Association's State of the Air report provides additional context on long-term health risks from air pollution exposure.
Related Cities in California
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Frequently Asked Questions
San Diego, California has a current median AQI of 67, which falls in the "Moderate" range. The area has received an Air Quality Grade of D (36/100) based on 10 years of EPA monitoring data.
Air quality in San Diego, California is stable over the past decade. The median AQI has changed by +2 points from 2014 to 2023.
San Diego, California averages 32 unhealthy air quality days per year over the past 5 years. On these days, sensitive groups including children, the elderly, and those with respiratory conditions should limit outdoor activity.
The primary pollutant affecting San Diego, California is Fine Particulate Matter (PM2.5). This is the dominant contributor to elevated AQI readings in the San Diego County area.
San Diego, California averages 32 unhealthy air days per year. With frequent unhealthy air days, asthma patients should use a HEPA air purifier indoors and check AQI before any outdoor activity. The primary pollutant is Fine Particulate Matter (PM2.5), which is a known asthma trigger.
With a median AQI of 67 (Moderate), outdoor exercise in San Diego, California is safe most days, though sensitive individuals should check daily AQI before intense workouts. San Diego, California averages 32 days per year when athletes should move workouts indoors.