An air quality alert is in effect for all of Massachusetts today due to smoke from Canadian wildfires, and it could be the worst air quality day the Boston area has seen all year.
The Massachusetts Department of Environmental Protection issued an alert for “fine particulates” in the air until midnight. New Hampshire is also under an air quality alert.
“Air is unhealthy for sensitive children and adults, such as those with asthma, lung or heart disease, and older adults,” the department said. “Sensitive children and adults should limit prolonged outdoor activity.”
The highest concentration of smoke is expected to be in western Massachusetts, the department said.
CBS Boston 
The yellow dots on the map represent the air quality reading stations registering a “moderate” air quality level as of 9 a.m. Monday.
Why is the sun red today?
The hazy sky is visible on satellite imagery, and it’s very clear and obvious to the naked eye when you step outside. It was causing ground delays averaging about 52 minutes at Logan Airport on Monday afternoon due to low visibility.
That haze you see is not cloudiness, but instead, mainly from the Canadian wildfires raging throughout Saskatchewan and Alberta.
The wind direction at upper levels of the atmosphere is aligned perfectly to carry the smoke nearly 2,000 miles from parts of central and northern Canada right down into New England.
CBS Boston 
Weather models show the highest concentration of wildfire smoke over parts of southern New England Monday afternoon. Combine that with some ground level ozone (thanks to a rather hot forecast) and you have, most likely, the worst air quality day of the summer thus far our region.
Air quality forecast
We do expect some improvement by Tuesday. There will still be some smoke in our atmosphere, however, air quality levels are not currently forecast to be unhealthy.
We will continue to update that forecast as new data comes in.
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