Climate hazards: Winter storms

Winter storms

Winter storms can include snowfall events, freezing rain, ice storms, and rain-on snow events. Winter storms can happen in the spring and fall, not just in winter.

Climate change is increasing the amount of winter precipitation and winter temperatures, although average winter temperatures are projected to remain below 0°C, on average, by the 2080s. This means that Calgary will continue to experience the high impact frozen and freezing precipitation events and heavy snow loads that often occur when temperatures near, but remain below, 0°C.

In 2014, the “Snowtember” event brought heavy snowfall in late summer which, because trees hadn’t yet shed their leaves, damaged half the trees in the city. This extremely heavy loading on trees and overhead infrastructure generated $17.4 million in insured costs alone.

Around your home, a really heavy snow load or ice storm can put significant stress on your roof, with the potential to damage (collapse) your roof and cause ice dams. Snow and ice storms can also damage infrastructure and cause power failures (e.g., downing of overhead power lines). 

Winter storm vulnerability

All communities within the city are equally exposed to winter storms. Consider the following questions. The more questions you answer as YES, the more vulnerable your home and property may be to winter storm damage.

Question Yes/No
Has your home ever been damaged by heavy snowfall or freezing rain?
Do you have flat or almost flat roof?
Do you have older, single-pane or low-quality windows?
Do you have a complex roof design with obstructions where snow and ice can collect?
Do you have skylights?
Is there any vegetation that overhangs your roof and contributes to blockages in roof drainage systems or that could break off and damage your roof or property?
Is your attic/roof poorly insulated? If so, snow loads on your roof can melt and cause ice damming.

How to reduce winter storm impacts

Some of the most impactful measures to reduce impacts to your home and property from winter storms include:

  • If building new, choose a roof structure with a steeper slope. Complex roof structures, and flatter roofs, are more susceptible to damage from winter storms.
  • If building new or replacing your roof, install a continuous underlayment of moisture or ice-and-water shield over the entire roof surface to protect against water and ice penetration.
  • Improve insulation and venting of your attic to reduce risk of ice damming on your roof.
  • Refer to the Winter Maintenance Checklist to check the exterior of your home after a major snowstorm. 
  • Prune trees for structural health as required by a certified arborist.

For more information about protecting your home and property from winter storms, refer to the Institute for Catastrophic Loss Reduction’s Homeowner Guide: Protect Your Home From Snow and Ice Storms.

For more information about staying safe before, during, and after a winter storm, visit What to do during a winter storm.

Disclaimer:  The content of the Climate Ready Home Guide is for informational purposes only and cannot be construed as technical advice with respect to any particular building(s) or construction project(s). The Climate Ready Home Guide does not recommend or endorse specific products or companies. All products and measures should be installed by a professional contractor, according to manufacturer specifications and following all City Bylaws and codes.