US air quality alerts: New York, New Jersey, Pennsylvania among 9 states hit by Canadian wildfire smoke
Air quality alerts were issued across the Northeast and Midwest US on August 5 due to elevated PM2.5 levels from Canadian wildfire smoke. Affected states include New Jersey, New York, Connecticut, Pennsylvania, Massachusetts, Vermont, Michigan, Wisconsin, and Indiana.
National Weather Service has issued a series of Air Quality Alerts across the northeastern and midwestern United States for August 5 as wildfire smoke from Canada continues to drift southward, blanketing large swaths of the country in hazardous fine particulate matter (PM2.5).
NWS said residents in New Jersey, New York, Connecticut, Pennsylvania, Massachusetts, Vermont, Michigan, Wisconsin, and Indiana have been warned to limit outdoor activity due to unhealthy air conditions, especially for sensitive populations.
Air Quality Action days declared
New Jersey, New York, and Connecticut all remain under Air Quality Action Days through midnight tonight. The New Jersey Department of Environmental Protection has flagged Bergen, Passaic, Hudson, Essex, and Union counties, while the New York State Department of Environmental Conservation extended the alert to all five NYC boroughs and counties north of the city including Westchester, Rockland, Orange, and Putnam.
The Connecticut Department of Energy and Environmental Protection issued alerts for Fairfield, New Haven, and Middlesex counties until 11 PM.
Health risks for vulnerable groups
Across all states, officials are advising sensitive individuals — including children, older adults, and those with asthma, lung, or heart disease — to limit strenuous or prolonged outdoor activities. The New York State Department of Health echoed this concern, urging those at risk to consider consulting a physician if symptoms such as shortness of breath, wheezing, or chest discomfort develop.
Understanding AQI and PM2.5
The Air Quality Index (AQI) values in affected areas are expected to exceed 100, placing many regions in the "Unhealthy for Sensitive Groups" category. Fine particulates (PM2.5), the primary pollutant, are microscopic particles that can penetrate deep into the lungs and bloodstream, exacerbating existing health issues and triggering new symptoms in vulnerable populations.
Canadian wildfire smoke
States such as Michigan, Wisconsin, and Indiana reported direct impacts from Canadian wildfire smoke, particularly from fires in Manitoba and Ontario. High pressure systems have trapped smoke close to the ground, worsening air quality.
In Michigan, counties across the northern and central parts of the state were affected, with concentrations expected to ease by Wednesday. Meanwhile, Wisconsin’s Department of Natural Resources expects smoke to persist throughout the day, with heavier conditions in the northeast.
Other state advisories
Vermont: Counties of Bennington and Windham are under alert through midnight due to smoke-driven PM2.5 levels.
Massachusetts: An alert is in effect from 11 AM to 11 PM for Fine Particulates.
Pennsylvania: Issued a Code Orange Alert, indicating unhealthy air for sensitive groups, especially in urban centers.
Indiana: Declared an Air Quality Action Day for fine particulates and advised reducing outdoor exposure.
What you can do
Officials across all regions recommend the following precautions:
Avoid or limit outdoor exertion, especially if you’re in a sensitive group.
Keep windows closed and use air purifiers or HVAC systems with MERV-13 filters or higher.
Avoid activities that worsen air quality, such as burning wood or refueling vehicles during the day.
Monitor symptoms such as coughing, difficulty breathing, chest tightness, or eye irritation — and seek medical advice if they worsen.
Check your local AQI at www.airnow.gov for real-time updates.