AIR QUALITY CT

Air Quality in Hartford, CT: Moderate (66 AQI)

AQI 66 · Moderate · Ozone · Updated 2026-07-18

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

Data: EPA AirNow, FEMA National Risk Index Last verified: 2026-07-18

Average AQI

Moderate

AQI Category

108

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. Hartford's average AQI of 66 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: Hartford, CT

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 Hartford

AQI varies across Hartford's 36 ZIP codes based on proximity to pollution sources and local geography.

ZIP Code	AQI	Category	Wildfire	Mold
06101	66	Moderate	23	38	View report →
06102	66	Moderate	23	47	View report →
06103	66	Moderate	23	49	View report →
06104	66	Moderate	23	47	View report →
06105	66	Moderate	23	58	View report →
06106	66	Moderate	23	55	View report →
06112	66	Moderate	23	55	View report →
06114	66	Moderate	23	58	View report →
06115	66	Moderate	23	38	View report →
06120	66	Moderate	23	52	View report →
06123	66	Moderate	23	47	View report →
06126	66	Moderate	23	47	View report →
06132	66	Moderate	23	47	View report →
06134	66	Moderate	23	47	View report →
06140	66	Moderate	23	47	View report →

Showing 15 of 20 ZIP codes. View all.

Air Quality Overview

Hartford, Connecticut has moderate air quality with an average AQI of 66. 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 Hartford

AQI varies across Hartford's 36 ZIP codes based on proximity to pollution sources, traffic patterns, and local geography:

ZIP Code	AQI	Category	Wildfire Risk	Mold Score
06101	66	Moderate	23	38
06102	66	Moderate	23	47
06103	66	Moderate	23	49
06104	66	Moderate	23	47
06105	66	Moderate	23	58
06106	66	Moderate	23	55
06112	66	Moderate	23	55
06114	66	Moderate	23	58
06115	66	Moderate	23	38
06120	66	Moderate	23	52
06123	66	Moderate	23	47
06126	66	Moderate	23	47
06132	66	Moderate	23	47
06134	66	Moderate	23	47
06140	66	Moderate	23	47

Showing 15 of 36 ZIP codes. Check your specific ZIP for detailed data.

Wildfire Smoke Risk

Hartford has an elevated wildfire smoke risk with an average smoke risk score of 23 (scale 0-100). There have been 107 fires recorded within 100 km of city ZIP codes.

Metric	Value
Avg. smoke risk score	23
Max smoke risk score	23
Fires within 100 km	107
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

Hartford has an average mold risk score of 48 out of 100, with 4 ZIP codes in the high-risk category.

Factor	Value
Mold risk score	48/100
Average humidity	68% RH
High-risk ZIPs	4
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 66), 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

Hartford vs. Nearby Connecticut Cities

How Hartford's air quality compares to nearby cities:

City	AQI	Category	Population
Hartford	66	Moderate	120,347
Waterbury	152	Unhealthy	114,453
New Haven	163	Unhealthy	131,106
Stamford	151	Unhealthy	135,720

ZIP Codes in Hartford

Hartford covers 36 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 Hartford?

Hartford's average AQI is 66 (Moderate). Air quality is acceptable, but unusually sensitive individuals may experience respiratory symptoms during peak pollution times.

How many unhealthy air days does Hartford have?

Hartford experiences 108 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 Hartford?

The average Air Quality Index (AQI) in Hartford is 66, 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 Hartford?

Hartford has a wildfire risk score of 23 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 Hartford?

Hartford has a mold risk score of 48 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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