AIR QUALITY MO

Air Quality in Ballwin, MO: Moderate (57 AQI)

AQI 57 · Moderate · PM2.5 · Updated 2026-05-03

Ballwin's air quality is moderate. Unusually sensitive people should consider reducing prolonged outdoor exertion.

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

Average AQI

Moderate

AQI Category

Wildfire Risk

Mold Score

ZIP Codes

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. Ballwin's average AQI of 57 falls in the "Moderate" range.

Air Quality by ZIP Code in Ballwin

AQI varies across Ballwin's 4 ZIP codes based on proximity to pollution sources and local geography.

ZIP Code	AQI	Category	Wildfire	Mold
63011	57	Moderate	13	55	View report →
63021	57	Moderate	13	50	View report →
63022	57	Moderate	13	31	View report →
63024	57	Moderate	13	31	View report →

Air Quality Overview

Ballwin, Missouri has moderate air quality with an average AQI of 57. Air quality is acceptable, though some pollutants may be a concern for a small number of people who are unusually sensitive to air pollution. The dominant pollutant 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 Ballwin

AQI varies across Ballwin's 4 ZIP codes based on proximity to pollution sources, traffic patterns, and local geography:

ZIP Code	AQI	Category	Wildfire Risk	Mold Score
63011	57	Moderate	13	55
63021	57	Moderate	13	50
63022	57	Moderate	13	31
63024	57	Moderate	13	31

Wildfire Smoke Risk

Ballwin has an elevated wildfire smoke risk with an average smoke risk score of 13 (scale 0-100). There have been 28 fires recorded within 100 km of city ZIP codes.

Metric	Value
Avg. smoke risk score	13
Max smoke risk score	13
Fires within 100 km	28
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

Ballwin has an average mold risk score of 42 out of 100, with 1 ZIP codes in the high-risk category.

Factor	Value
Mold risk score	42/100
Average humidity	68% RH
High-risk ZIPs	1
Peak season	summer 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 moderate air quality (AQI 57), most people can be active outdoors. Sensitive groups should take precautions:

Sensitive groups (asthma, COPD, heart disease): consider reducing prolonged outdoor exertion
Keep windows closed on high-pollution days
Use a HEPA air purifier in main living areas
Check AirNow.gov before outdoor exercise

Ballwin vs. Nearby Missouri Cities

How Ballwin's air quality compares to nearby cities:

City	AQI	Category	Population
Ballwin	57	Moderate	1,111,000
Earth City	81	Moderate	1,111,000
Glencoe	81	Moderate	1,111,000
Chesterfield	81	Moderate	1,113,079

ZIP Codes in Ballwin

Ballwin covers 4 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.

Frequently Asked Questions

Is the air safe to breathe in Ballwin?

Ballwin's average AQI is 57 (Moderate). Air quality is acceptable, but unusually sensitive individuals may experience respiratory symptoms during peak pollution times.

How many unhealthy air days does Ballwin have?

Ballwin has zero recorded unhealthy air quality days, which is excellent. Air quality can still vary seasonally due to wildfire smoke, pollen, or industrial activity.

What is the AQI in Ballwin?

The average Air Quality Index (AQI) in Ballwin is 57, categorized as Moderate. The primary pollutant is PM2.5. AQI ranges from 0-500, where 0-50 is Good, 51-100 Moderate, 101-150 Unhealthy for Sensitive Groups, and 151+ Unhealthy.

What is the wildfire risk in Ballwin?

Ballwin has a wildfire risk score of 13 out of 100. Low wildfire risk means smoke events are uncommon, but regional fires can still temporarily affect air quality.

Is mold a concern in Ballwin?

Ballwin has a mold risk score of 42 out of 100, based on humidity, precipitation, and temperature data. Maintain good ventilation and address any water intrusion promptly to prevent mold growth.

Home → Cities → Missouri → Ballwin, MO → Air Quality