People were awoken again this morning (December 30th) by loud "Kaboom!" noises—similar to what many heard on Christmas Eve and Christmas Morning. Many were jolted from their sleep, and had to get up and look around the house. They reported their walls shook, and that it sounded like the roof was collapsing.
These are, apparently, Frost Quakes—aka Cyroseisms—that struck, rare, localized seismic events that occur when a sudden drop in temperature freezes the groundwater, which then expands and cracks the soil and rock.
Indeed, CP24.com reports "loud boom-like noises that rippled through parts of southern Ontario early Monday morning were likely caused by frost quakes, police say."
People in York Region, Kawartha Lakes and Peterborough heard multiple booms in the early morning hours.
The explosive expansion of air is similar to a thunderclap, says CP24 meteorologist Bill Coulter.
Or just rock out to the below...