Winter/Calgary Hoar Frost.

When conditions are just right, and this only happens once or twice a year, fog rolls in with a very high moisture content. The surface temperature is considerably colder and when one meets the other, Hoar Frost is the result.
If it clears the following day and the skies are blue it can be magical.
Today, it was white skies and white everything else.
But the results can be every bit as beautiful.