Air quality alert for Wednesday in New York, New Jersey, and Connecticut
NEW YORK CITY and a wide stretch of the Tri-State Area are under an Air Quality Alert today, Wednesday, June 4, 2025, as ground-level ozone concentrations are expected to approach or exceed unhealthy levels. The National Weather Service issued the advisory in response to a mix of sunny skies, hot temperatures, and light southwest winds, which are creating ideal conditions for ozone formation—particularly along the I-95 corridor.
The alert remains in effect from 11 a.m. to 11 p.m. and includes key regions such as:
In New York:
New York City and the Hudson Valley
In New Jersey:
Bergen, Passaic, Hudson, Essex, Mercer, Middlesex, and Union Counties
In Connecticut:
Fairfield, New Haven, Middlesex, and Northern New London Counties
Who is most at risk and when?
The most critical hours fall during the afternoon and early evening, when ozone levels peak. Sensitive individuals, including young children, the elderly, and those with asthma or other respiratory illnesses, should avoid strenuous outdoor activity during this time. This also applies to people who exercise or work outdoors.
What’s causing the ozone spike?
Ground-level ozone is not directly emitted but is formed through sunlight-activated reactions involving nitrogen oxides (NOx) and volatile organic compounds (VOCs). These precursors are released by vehicles, construction equipment, industries, and even gasoline vapors.
Today’s weather—hot sun, low wind, and urban emissions—is accelerating this reaction, worsening air pollution, especially in densely populated zones like Manhattan, Jersey City, and New Haven.
Smoke haze from Canada adds to the issue
To complicate matters, smoke from Canadian wildfires is causing a haze across the region. Although this smoke is high in the atmosphere and not expected to affect ground-level air quality, it’s contributing to a visible haze and a dimmed sunset. Cameras in Queens captured a partially obscured sun as smoke filtered through the skies.
Protecting yourself and reducing pollution
During ozone peaks, being indoors helps reduce exposure. People noticing coughing, chest discomfort, or shortness of breath should contact their physician. At night, ozone levels typically drop, but pollution mitigation steps are still crucial throughout the day.
Residents are strongly urged to reduce emissions and energy use through:
Carpooling or mass transit, as automobile traffic is a major pollution source
Limiting vehicle trips and combining errands
Using fans instead of air conditioning when possible, or setting A/C to 78°F (25.5°C)
Turning off unused lights and appliances
Shading windows to maintain cooler indoor temperatures
Running household appliances only after 7 p.m., including dryers, dishwashers, and water heaters
Adjusting fridge and freezer settings to efficient levels
Avoiding outdoor burning and indoor sources of fine particles, such as cigarette smoke
This alert reflects a broader trend of increasing ozone events during the warmer months across urban Northeastern U.S., often aggravated by weather patterns and wildfire activity from Canada.
Stay tuned for any further advisories throughout the day, especially if weather conditions evolve.
