AIR QUALITY MA

Air Quality in Harwich Port, MA: Moderate (65 AQI)

AQI 65 · Moderate · Ozone · Updated 2026-07-18

Harwich Port'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

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. Harwich Port's average AQI of 65 falls in the "Moderate" range.

Air Quality by ZIP Code in Harwich Port

Harwich Port is covered by a single ZIP code, so one AQI profile applies citywide. Air quality still shifts with wind, season and proximity to pollution sources.

ZIP Code	AQI	Category	Wildfire	Mold
02646	65	Moderate	11	50	View report →

Air Quality Overview

Harwich Port, Massachusetts has moderate air quality with an average AQI of 65. 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 Harwich Port

AQI varies across Harwich Port's 1 ZIP code based on proximity to pollution sources, traffic patterns, and local geography:

ZIP Code	AQI	Category	Wildfire Risk	Mold Score
02646	65	Moderate	11	50

Wildfire Smoke Risk

Harwich Port has an elevated wildfire smoke risk with an average smoke risk score of 11 (scale 0-100).

Metric	Value
Avg. smoke risk score	11
Max smoke risk score	11
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

Harwich Port has an average mold risk score of 50 out of 100.

Factor	Value
Mold risk score	50/100
Average humidity	68% RH
High-risk ZIPs	0
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 65), 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

Harwich Port vs. Nearby Massachusetts Cities

How Harwich Port's air quality compares to nearby cities:

City	AQI	Category	Population
Harwich Port	65	Moderate	1,715
Gilbertville	130	USG	1,715
Ashfield	130	USG	1,711
Leverett	130	USG	1,704

ZIP Codes in Harwich Port

Harwich Port 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 Harwich Port?

Harwich Port's average AQI is 65 (Moderate). Air quality is acceptable, but unusually sensitive individuals may experience respiratory symptoms during peak pollution times.

How many unhealthy air days does Harwich Port have?

Harwich Port experiences 3 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 Harwich Port?

The average Air Quality Index (AQI) in Harwich Port is 65, 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 Harwich Port?

Harwich Port has a wildfire risk score of 11 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 Harwich Port?

Harwich Port has a mold risk score of 50 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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