High Air Quality Health Index values reported across parts of the GTA Thursday

Thursday, February 13, 2014, 12:32 PM -

Environment Canada issued a special air quality statement Thursday morning warning of high index values.

"Today is a day with high Air Quality Health Index (AQHI) values of 7 to 9 from Hamilton the the Greater Toronto Area," said EC in the statement. "This is due to elevated levels of nitrogen dioxide in the air as the result of light winds and a stagnate air mass."

AQHI: Stay on top of the current AQHI values in your area.

Although we see these types of advisories more often in the summer months, it's not unheard of in the winter either.

"We have an inversion in place, which is not uncommon in the winter," says Monica Vaswani, a meteorologist at The Weather Network. "All that means is that we have colder air at the surface and warmer air aloft. As a result, this allows for a stagnant air mass and that coupled with light winds can result in pollutants getting trapped in the atmosphere."

As the winds pick up Thursday afternoon the AQHI values are expected to improve to "moderate," but there is still a risk that the values may go back up to near "7" Thursday night.

"Canadians enjoy outdoor activities year round and the Air Quality Health Index can help us decide the best times to be active, regardless of the season," Christina Daly of Health Canada told theweathernetwork.com.

You can check the air quality reading by heading to the Air Quality Report on our website.