For Eastern Canada you can look
here - although now, at mid-September, it is really too early to predict accurately and I notice there is not yet any info on that link for Ontario and East.
From my memory of previous years in Central Ontario, my guess is that Fall colour will be slightly later than usual this year due to the cool wet Summer and the very healthy green growth we have had. To my eye, the first signs of yellowing are about 10 days later than usual and have yet to show significantly. If correct, this would put the height of colour in Algonquin Park back to the second week of October.