AIR QUALITY SC

Air Quality in Charleston, SC: Moderate (61 AQI)

AQI 61 · Moderate · Ozone · Updated 2026-05-03

Charleston'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

Unhealthy Days

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. Charleston's average AQI of 61 falls in the "Moderate" 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: Charleston, SC

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 Charleston

AQI varies across Charleston's 16 ZIP codes based on proximity to pollution sources and local geography.

ZIP Code	AQI	Category	Wildfire	Mold
29401	61	Moderate	35	75	View report →
29402	61	Moderate	35	52	View report →
29403	61	Moderate	35	70	View report →
29406	61	Moderate	40	56	View report →
29407	61	Moderate	35	65	View report →
29409	61	Moderate	35	56	View report →
29412	61	Moderate	35	60	View report →
29413	61	Moderate	40	39	View report →
29414	61	Moderate	35	51	View report →
29416	61	Moderate	40	39	View report →
29417	61	Moderate	40	44	View report →
29422	61	Moderate	40	44	View report →
29423	61	Moderate	40	39	View report →
29424	61	Moderate	35	56	View report →
29425	61	Moderate	35	44	View report →

Showing 15 of 16 ZIP codes. View all.

Air Quality Overview

Charleston, South Carolina has moderate air quality with an average AQI of 61. 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 Ozone.

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: Ozone

Ground-level ozone forms when pollutants from cars, power plants, and industrial facilities react with sunlight. Unlike stratospheric ozone, ground-level ozone is harmful to breathe.

Health effects of ozone exposure:

Irritation of the respiratory system
Reduced lung function
Aggravation of asthma and chronic lung diseases
Increased susceptibility to respiratory infections

Peak times: Ozone levels are typically highest on hot, sunny afternoons. Exercise outdoors in the morning when levels are lower.

Air Quality by ZIP Code in Charleston

AQI varies across Charleston's 16 ZIP codes based on proximity to pollution sources, traffic patterns, and local geography:

ZIP Code	AQI	Category	Wildfire Risk	Mold Score
29401	61	Moderate	35	75
29402	61	Moderate	35	52
29403	61	Moderate	35	70
29406	61	Moderate	40	56
29407	61	Moderate	35	65
29409	61	Moderate	35	56
29412	61	Moderate	35	60
29413	61	Moderate	40	39
29414	61	Moderate	35	51
29416	61	Moderate	40	39
29417	61	Moderate	40	44
29422	61	Moderate	40	44
29423	61	Moderate	40	39
29424	61	Moderate	35	56
29425	61	Moderate	35	44

Showing 15 of 16 ZIP codes. Check your specific ZIP for detailed data.

Wildfire Smoke Risk

Charleston has an elevated wildfire smoke risk with an average smoke risk score of 37 (scale 0-100). There have been 84 fires recorded within 100 km of city ZIP codes.

Metric	Value
Avg. smoke risk score	37
Max smoke risk score	40
Fires within 100 km	84
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

Charleston has an average mold risk score of 52 out of 100, with 7 ZIP codes in the high-risk category.

Factor	Value
Mold risk score	52/100
Average humidity	73% RH
High-risk ZIPs	7
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 61), 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

Charleston vs. Nearby South Carolina Cities

How Charleston's air quality compares to nearby cities:

City	AQI	Category	Population
Charleston	61	Moderate	327,422
Hanahan	71	Moderate	327,422
Huger	71	Moderate	327,422
Columbia	61	Moderate	323,067

ZIP Codes in Charleston

Charleston covers 16 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 Charleston?

Charleston's average AQI is 61 (Moderate). Air quality is acceptable, but unusually sensitive individuals may experience respiratory symptoms during peak pollution times.

How many unhealthy air days does Charleston have?

Charleston experiences 16 unhealthy air quality days per year on average. During these days, everyone — not just sensitive groups — should reduce prolonged outdoor exertion.

What is the AQI in Charleston?

The average Air Quality Index (AQI) in Charleston is 61, categorized as Moderate. The primary pollutant is Ozone. 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 Charleston?

Charleston has a wildfire risk score of 37 out of 100. Moderate wildfire risk means smoke events are possible. Having a HEPA air purifier available is recommended.

Is mold a concern in Charleston?

Charleston has a mold risk score of 52 out of 100, based on humidity, precipitation, and temperature data. Maintain good ventilation and address any water intrusion promptly to prevent mold growth.

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