San Diego vs Modesto Air Quality Comparison
Which city has cleaner air right now, from the latest EPA AirNow AQI
As of November 8, 2026, San Diego, CA has cleaner air than Modesto, CA — AQI 34 (Good) vs 64 (Moderate), a gap of 30 AQI points in the latest EPA AirNow observations. Lower AQI means cleaner air. San Diego's reading is driven by O3 and Modesto's by PM2.5.
San Diego, CA
Good
Modesto, CA
Moderate
Summary
San Diego has 30 points better air quality
San Diego has an AQI of 34 compared to 64
Extra Protection for Modesto Homes
Air quality in Modesto is moderate (AQI 64), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.
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5-Day Forecast Comparison
| Day | San Diego | Modesto | Better |
|---|---|---|---|
| Today | AQI 54 | AQI 60 | San Diego |