There have been reports of a rather unsual phenomenon in Northwestern Ontario since the weekend snowfall.
Some say they have seen brown snow.
David Phillips of Environment Canada believes soot from forest fires in the Southwestern U.S. is to blame.
Phillips says based on air masses travelling across the continent, the soot mixed in with the snowfall creating so-called brown snow.
In other instances, he adds dust from the Gobi Desert in China has been blamed on the rare occurence.