Why Calgary has so many spectacular icicles

The reason Calgary homes have so many icicles hanging from the eaves has to do with the snowfall and temperature swings, explains a scientist.

Many range from 3 to 4 feet long

Recent weather has formed some pretty impressive icicles around Calgary. 1:58

Recent weather has formed some pretty impressive icicles around Calgary.

The reason so many Calgary homes have icicles hanging from the eaves has to do with the recent snowfall and temperature swings — cold nights and relatively warm days, said Telus Spark​ scientist Devon Hamilton.

"You've got snow accumulated on somebody's roof — and we've had a little bit snowfall in the last week or so. It begins to melt and as it melts, it begins to drip," he said.

"As it's dripping it can refreeze, especially if it's getting melted because of sunlight or because of heat escaping from a home. So that's also why you see them on the eaves of people's houses because that's a natural exit point for heating coming out of your house." 

The conditions in Calgary are perfect for helping an icicle to grow long quickly, he said. Water droplets moving down the surface of the icicle release heat energy as they freeze.

"That warm air, that is given up by those ice droplets that are freezing, rises up and forms a nice blanket. Which means at the base, or the thicker part of the icicle, you are more likely to have liquid flowing. And as it gets down to the tip, the air is a little bit cooler, you got less of that warm blanket and that means it's likely to freeze."

Hamilton said some people who have a lot of icicles might want to check their insulation.

"It might be a good idea for you to check the insulation in your attic because that means you're leaking heat and that's melting some of that snow as well," said Hamilton.


To encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.

By submitting a comment, you accept that CBC has the right to reproduce and publish that comment in whole or in part, in any manner CBC chooses. Please note that CBC does not endorse the opinions expressed in comments. Comments on this story are moderated according to our Submission Guidelines. Comments are welcome while open. We reserve the right to close comments at any time.