AIR QUALITY IL

Air Quality in Granite City, IL: Moderate (55 AQI)

AQI 55 · Moderate · PM2.5 · Updated 2026-05-03

Granite City'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. Granite City's average AQI of 55 falls in the "Moderate" range.

Air Quality by ZIP Code in Granite City

AQI varies across Granite City's 1 ZIP codes based on proximity to pollution sources and local geography.

ZIP Code	AQI	Category	Wildfire	Mold
62040	55	Moderate	5	63	View report →

Air Quality Overview

Granite City, Illinois has moderate air quality with an average AQI of 55. 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 Granite City

AQI varies across Granite City's 1 ZIP codes based on proximity to pollution sources, traffic patterns, and local geography:

ZIP Code	AQI	Category	Wildfire Risk	Mold Score
62040	55	Moderate	5	63

Wildfire Smoke Risk

Granite City has a low wildfire smoke risk with an average smoke risk score of 5 (scale 0-100). However, smoke from distant wildfires can temporarily degrade air quality even in low-risk areas.

Metric	Value
Avg. smoke risk score	5
Max smoke risk score	5
Fires within 100 km	0
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

Granite City has an average mold risk score of 63 out of 100, with 1 ZIP codes in the high-risk category.

Factor	Value
Mold risk score	63/100
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 55), 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

Granite City vs. Nearby Illinois Cities

How Granite City's air quality compares to nearby cities:

City	AQI	Category	Population
Granite City	55	Moderate	36,127
Machesney Park	101	USG	35,663
Edwardsville	113	USG	36,643
Dieterich	N/A	N/A	35,589

ZIP Codes in Granite City

Granite City covers 1 ZIP code. 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 Granite City?

Granite City's average AQI is 55 (Moderate). Air quality is acceptable, but unusually sensitive individuals may experience respiratory symptoms during peak pollution times.

How many unhealthy air days does Granite City have?

Granite City 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 Granite City?

The average Air Quality Index (AQI) in Granite City is 55, 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 Granite City?

Granite City has a wildfire risk score of 5 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 Granite City?

Granite City has a mold risk score of 63 out of 100, based on humidity, precipitation, and temperature data. This is elevated — proper ventilation, dehumidifiers, and regular inspection of basements and bathrooms are important.

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