Researchers have concluded that a rogue wave spotted near the coast of Canada in 2020 (approximately the height of a four-storey building) was the most extreme atypical natural phenomenon recorded to date.

These waves, which go by various names such as rogue or freak waves, usually form out of nowhere in the middle of the ocean. On 17 November 2020, the aforementioned wave was recorded by an ocean buoy belonging to the research company MarineLabs. The wave (and the buoy) were located about 7 km from Vancouver Island in British Columbia, Canada.
Simulation image of the MarineLabs wave