Quote : "He added that while October wildfires are not common, they are not unheard of in southern Alberta, either."

This statement seems a bit vague. 

Please permit me to rephrase my original question.

Is it "unheard of" to have 20 active wildfires burning in Alberta this late in October (seven of which just started in the past 24 hours) ?

http://wildfire.alberta.ca/reports/sitrep.html