Record-breaking heat wave in Ottawa is 'summer's last hurrah'

The heat wave that set a record Wednesday is a distant relative of Hurricane Michael coming ashore in Florida — not caused by the hurricane, but related in the sense that the same flow of hot, southern air is driving both events.
Our muggy air is not home-cooked. Ottawa sunshine is not powerful enough to produce mid-20s heat in October.
Instead, Environment Canada’s David Phillips explains that this week’s warm air has been pre-heated in the south and central United States and