Southwestern Ontario's hot and sticky weather is back, but a close cousin — serious, even dangerous smog — is noticeably missing.

The London region hasn't had a smog advisory for 18 months, a dramatic reversal for a region that once suffered through dozens of smog days a year and traditionally has some of Canada's dirtiest air. Rewind just a decade ago, and the city couldn't go a few days without a smog advisory.

(READ the story from Sun News)

Photo by Joe Nicholl, Toronto, Ontario – CC Flickr