San Diego vs Riverside Air Quality Comparison
Which city has cleaner air right now, from the latest EPA AirNow AQI
As of September 23, 2026, San Diego, CA has cleaner air than Riverside, CA — AQI 58 (Moderate) vs 71 (Moderate), a gap of 13 AQI points in the latest EPA AirNow observations. Lower AQI means cleaner air. San Diego's reading is driven by PM2.5 and Riverside's by O3.
San Diego, CA
Moderate
Riverside, CA
Moderate
Summary
San Diego has 13 points better air quality
San Diego has an AQI of 58 compared to 71
Reduce Indoor Ozone in Riverside
Today's main pollutant in Riverside is ground-level ozone (AQI 71). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
Compare activated-carbon purifiers (for gases & ozone):
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5-Day Forecast Comparison
| Day | San Diego | Riverside | Better |
|---|---|---|---|
| Today | AQI 55 | AQI 101 | San Diego |