Data: EPA AirNow, FEMA National Risk Index Last verified: 2026-05-03

What is AQI?

The Air Quality Index (AQI) is a standardized scale from 0 to 500 that measures air pollution levels. 0-50 is "Good," 51-100 is "Moderate," 101-150 is "Unhealthy for Sensitive Groups," and above 150 is "Unhealthy" for everyone. AQI tracks five major pollutants: ground-level ozone, particulate matter (PM2.5 and PM10), carbon monoxide, sulfur dioxide, and nitrogen dioxide. Stockton's average AQI of 48 falls in the "Good" range.

How do wildfires affect air quality?

Wildfire smoke contains fine particulate matter (PM2.5) that can travel hundreds of miles and dramatically spike AQI readings. During fire season, even cities far from active fires can experience unhealthy air. HEPA air purifiers (rated for PM2.5) are the most effective indoor protection. Check AirNow.gov for real-time conditions during fire season.

Air Quality Map: Stockton, CA

Each dot represents a ZIP code. Color indicates AQI level. Tap a dot for details.

Good (0-50) Moderate (51-100) USG (101-150) Unhealthy (151+)

Air Quality by ZIP Code in Stockton

AQI varies across Stockton's 20 ZIP codes based on proximity to pollution sources and local geography.

ZIP Code	AQI	Category	Wildfire	Mold
95201	48	Good	26	25	View report →
95202	48	Good	26	43	View report →
95203	48	Good	26	46	View report →
95204	48	Good	25	49	View report →
95205	48	Good	26	43	View report →
95206	48	Good	26	29	View report →
95207	48	Good	25	38	View report →
95208	48	Good	20	25	View report →
95209	48	Good	25	34	View report →
95210	48	Good	25	31	View report →
95211	48	Good	25	21	View report →
95212	48	Good	25	25	View report →
95213	48	Good	26	21	View report →
95214	48	Good	26	21	View report →
95215	48	Good	26	46	View report →

Showing 15 of 20 ZIP codes. View all.

Air Quality Overview

Stockton, California has good air quality with an average AQI of 48. This means air pollution poses little or no risk. The dominant pollutant measured is PM2.5.

The Air Quality Index (AQI) is an EPA-standardized scale from 0 to 500. Values below 50 are "Good," 51-100 "Moderate," 101-150 "Unhealthy for Sensitive Groups," 151-200 "Unhealthy," 201-300 "Very Unhealthy," and above 300 "Hazardous."

Dominant Pollutant: PM2.5

PM2.5 (fine particulate matter) consists of particles smaller than 2.5 micrometers — about 30 times thinner than a human hair. These particles can penetrate deep into the lungs and enter the bloodstream.

Health effects of PM2.5 exposure:

• Short-term: coughing, shortness of breath, aggravated asthma
• Long-term: reduced lung function, cardiovascular disease, premature death
• Most vulnerable: children, elderly, people with heart or lung disease

Common sources in urban areas: vehicle exhaust, construction dust, industrial emissions, wildfire smoke, residential wood burning.

Air Quality by ZIP Code in Stockton

AQI varies across Stockton's 20 ZIP codes based on proximity to pollution sources, traffic patterns, and local geography:

Showing 15 of 20 ZIP codes. Check your specific ZIP for detailed data.

Wildfire Smoke Risk

Stockton has an elevated wildfire smoke risk with an average smoke risk score of 25 (scale 0-100). There have been 378 fires recorded within 100 km of city ZIP codes.

Metric	Value
Avg. smoke risk score	25
Max smoke risk score	26
Fires within 100 km	378
High-risk ZIP codes	0

Wildfire smoke contains PM2.5, carbon monoxide, and volatile organic compounds. Even short-term exposure can trigger asthma attacks and respiratory distress.

Indoor Mold Risk

Stockton has an average mold risk score of 31 out of 100.

Factor	Value
Mold risk score	31/100
Average humidity	57% RH
High-risk ZIPs	0
Peak season	winter high

Mold risk is influenced by humidity levels, housing age (older homes have more moisture issues), flood history, and water infrastructure quality. Indoor humidity above 60% creates favorable conditions for mold growth.

Signs of mold problems: musty odors, visible growth on walls or ceilings, worsening allergies indoors, condensation on windows. Professional mold testing ($300-$600) can identify hidden issues.

Health Recommendations

With good air quality (AQI 48), Stockton residents can enjoy outdoor activities without significant restrictions. General tips:

• Monitor AQI during wildfire season for temporary spikes
• Use HEPA air purifiers indoors if you have respiratory conditions
• Maintain indoor humidity between 30-50% to prevent mold

Stockton vs. Nearby California Cities

How Stockton's air quality compares to nearby cities:

ZIP Codes in Stockton

Stockton covers 20 ZIP codes. Air quality can vary by neighborhood based on proximity to highways, industrial areas, and green spaces. Check your specific ZIP code for localized data.

Data Sources

• Air quality: EPA AirNow — real-time and historical AQI data
• Wildfire risk: FEMA National Risk Index
• Mold risk: Derived from EPA, FEMA, Census ACS (humidity, housing age, flood history)
• Monthly AQI: EPA Air Quality Statistics

Updated daily.