I sing for the Cor Meibion Cymreig Montreal (top tenor)
I see this thread is a bit hoary itself.
We are just getting ready to sing Nos Galan this season and wanted the first verse in Welsh so I was just checking a bit.
You know.
As to the hoar frost.
One of the great natural disasters in Quebec some years back was the North American ice storm of 1998 (also known as Great Ice Storm of 1998 and Great Ice Storm '98) was a massive combination of five smaller successive ice storms which combined to strike a relatively narrow swath of land from eastern Ontario to southern Quebec to Nova Scotia in Canada, and bordering areas from northern New York to central Maine in the United States, in January 1998.
It caused massive damage to trees and electrical infrastructure all over the area, leading to widespread long-term power outages. Millions were left in the dark for periods varying from days to weeks, leading to more than 30 fatalities, a shut down of activities in large cities like Montreal and Ottawa, and an unprecedented effort in reconstruction of the power grid.

It was primarily caused by hoar frost, which is when the moisture in the air freezes directly on cold surfaces.
On our case, trees and electricity grid lines.
Without any rain or snow they become encased in ice. In Britain, I come from South Wales, this is usually a pretty and thin covering but here it was almost incredible.
The ice just grew everywhere.
I was evacuated from my home in the Richlieu valley by the army.
I lived in an area called the black triangle. We were without power for 28 days.
The average temperature at that time plunged to about minus 20. Work was shut down for a month.
So much for hoar frost.