The air quality index measures PM2.5, less than 2.5 microns particles, to determine the intensity of air pollution in cities.

In addition to the fires in Canada, several large wildfires in the Pacific Northwest are contributing smoke through that area and to the east. The largest fires are burning east of the spine of ...

Four firefighters were injured and two homes destroyed causing about $2 million in damage after an overnight fire in east Hamilton, Hamilton Fire Chief Dave Cunliffe says. Three firefighters had ...

A fast-moving brush fire sparked in hills above Altadena exploded to 10,600 acres by Wednesday, killed five people, damaged or destroyed between 200 and 500 homes and other structures while ...

It's a rapidly changing situation - these maps and pictures show the scale of the challenge, where the fires are and the ...

As major fires continue to rage in and around Los Angeles, help battling the blazes has come from across the country — and from across international borders, including from Canada and Mexico.