AIR QUALITY VT

Air Quality in Montpelier, VT: Good (42 AQI)

AQI 42 · Good · Ozone · Updated 2026-07-18

Montpelier's air quality is good. Air pollution poses little or no risk.

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

Average AQI

Good

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. Montpelier's average AQI of 42 falls in the "Good" range.

Air Quality Map: Montpelier, VT

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 Montpelier

AQI varies across Montpelier's 7 ZIP codes based on proximity to pollution sources and local geography.

ZIP Code	AQI	Category	Wildfire	Mold
05601	42	Good	11	45	View report →
05602	42	Good	11	63	View report →
05603	42	Good	11	51	View report →
05604	42	Good	11	41	View report →
05609	42	Good	11	51	View report →
05620	42	Good	11	41	View report →
05633	42	Good	11	45	View report →

Air Quality Overview

Montpelier, Vermont has good air quality with an average AQI of 42. This means air pollution poses little or no risk. The dominant pollutant measured 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 Montpelier

AQI varies across Montpelier's 7 ZIP codes based on proximity to pollution sources, traffic patterns, and local geography:

ZIP Code	AQI	Category	Wildfire Risk	Mold Score
05601	42	Good	11	45
05602	42	Good	11	63
05603	42	Good	11	51
05604	42	Good	11	41
05609	42	Good	11	51
05620	42	Good	11	41
05633	42	Good	11	45

Wildfire Smoke Risk

Montpelier has an elevated wildfire smoke risk with an average smoke risk score of 11 (scale 0-100). There have been 7 fires recorded within 100 km of city ZIP codes.

Metric	Value
Avg. smoke risk score	11
Max smoke risk score	11
Fires within 100 km	7
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

Montpelier has an average mold risk score of 48 out of 100, with 1 ZIP code in the high-risk category.

Factor	Value
Mold risk score	48/100
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 good air quality (AQI 42), Montpelier residents can enjoy outdoor activities without significant restrictions. General tips:

Monitor AQI during wildfire season for temporary spikes
Use HEPA air purifiers indoors if you have respiratory conditions
Maintain indoor humidity between 30-50% to prevent mold

Montpelier vs. Nearby Vermont Cities

How Montpelier's air quality compares to nearby cities:

City	AQI	Category	Population
Montpelier	42	Good	12,491
West Dummerston	136	USG	12,200
Milton	120	USG	13,347
Middlebury	130	USG	11,031

ZIP Codes in Montpelier

Montpelier covers 7 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 Montpelier?

Yes - Montpelier's average AQI is 42 (Good). Air pollution poses little or no risk for the general population.

How many unhealthy air days does Montpelier have?

Montpelier 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 Montpelier?

The average Air Quality Index (AQI) in Montpelier is 42, categorized as Good. 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 Montpelier?

Montpelier 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 Montpelier?

Montpelier 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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