Humidity. Not a word I’d associate with Calgary, a city where jumbo-sized bottles of hand and body lotion and humidifiers in every room of the house are not mere luxury items. The air is normally very dry here – Wikipedia claims that we have an average relative humidity of 55% in winter and 45% in summer. Once the cold, blistering winds and snow arrives, you begin to feel really parched. It makes you wish for a tropical vacation (okay, so EVERYTHING makes me wish for a tropical vacation…sigh).
Over the past few days, however, we’ve been completely immersed in a foggy gloom, and the humidity levels have risen dramatically. The temperature has been sitting below zero, however, so the water droplets from the low clouds have frozen and accumulated on the windward sides of trees, power lines, fences, etc. in a weather phenomenon called rime.
Rime is often confused with hoarfrost, but hoarfrost does not occur in foggy conditions. Hoarfrost is the freezing equivalent of dew. It occurs during times of high humidity, when the temperature of an exposed object becomes colder than the air surrounding it. The delicate flowery/feathery sheets of ice you sometimes see on windows are examples of hoarfrost.
Isn’t rime beautiful?
Is rime or hoarfrost a common cold weather occurrence where you live?
- Fall Hoarfrost – A Lens Full of Crystals (gogreygirl.wordpress.com)