Air quality alert for NYC area Wednesday, as Canadian wildfire smoke creates hazy conditions
New York City and some of the surrounding area are under an air quality alert Wednesday. The alert will be in effect from 11 a.m. to 11 p.m.
New York officials say the alert will impact the city, along with Dutchess, Orange, Putnam, Rockland, Sullivan, Ulster and Westchester counties. Long Island and the Jersey Shore are not expected to be impacted.
The air quality health advisory was updated Wednesday morning to include Western New York farther upstate, including Cattaraugus, Chautauqua, Erie, Genesee, Niagara, Orleans, and Wyoming counties.
The alert comes as hundreds of wildfires are burning across Canada, blowing smoke into parts of the U.S.
Why is there an air quality alert?
Smoke and haze continue to drift into the Tri-State region from Canada's prairie provinces. This will lead to hazy sunshine throughout the day.
The cause of this particular air quality alert, however, is ozone. New York City's air quality often suffers in the summer, most notably during heat waves as the result of higher temperatures and humidity levels. Stagnant air traps pollutants from cars and factories, creating high levels of fine particulates that react to sunlight, leading to or worsening respiratory issues. Ozone levels generally reduce at night and can be mitigated by curtailing the use of cars in favor of mass transit, officials say.
Sometimes, though, air quality alerts have nothing to do with pollution. In June 2023, northerly winds funneled smoke from wildfires in the Canadian province of Quebec directly into New York City. This led to an extremely hazardous Air Quality Index of 484 -- not only the highest level ever recorded in the city, but the worst air quality in the entire world on that date.
Air Quality Index (AQI) explained
The Air Quality Index measures air pollution and the associated health risks.
The system has six ratings:
- Good (green): 0 to 50
- Moderate (yellow): 51 to 100
- Unhealthy for sensitive groups (orange): 101 to 150
- Unhealthy (red): 151 to 200
- Very unhealthy (purple): 201 to 300
- Hazardous (marron): 301 and higher
An air quality alert is issued when the AQI exceeds 100. Today, it's expected to be around 105.
Sensitive groups include people who have a heart or lung disease, as well as older adults, children and pregnant women.
Why are the sun and moon red?
Smoke from the wildfires can sometimes cause the sun and moon to appear with a reddish glow.
The color of the sky is determined by how sunlight interacts with particles in the air. So when smoke introduces more particulate matter, it can also impact the color.
Matt Sitkowski, the science editor in chief at The Weather Channel, explained that blue-colored light has shorter wavelengths and red-colored light has longer ones.
"When smoke is in the atmosphere, it not only makes the sun dimmer, it increases the amount and size of particulate matter in the atmosphere that absorbs more of the shorter wavelengths, leaving longer wavelengths to reach our eyes," he told CBS News in a previous interview.
NYC weather forecast this week
Temperatures will continue to rise Wednesday, reaching the mid-to-upper 80s by the afternoon hours. Along with those rising temperatures will come increasingly humid conditions. For tonight, despite the haze, skies will remain mostly clear with lows in the 60s.
Thursday looks to be the hottest day of the year so far, with highs in the upper 80s to low 90s for most of the area, except coastal areas, where highs will only reach the 70s. Humidity levels will also continue to rise, and there will be a stray chance of an afternoon/evening thunderstorm for the northwestern suburbs.
As for the smoke and haze, it will remain in place as well.
Friday will be partly cloudy, warm and humid with a chance of thunderstorms. Saturday looks to be less warm but still humid with another chance of storms.
Stick with our First Alert Weather team for the latest forecast, live radar and and weather alerts.
