Damage cost from Calgary's July hailstorm nearly double of original estimate
Storm is estimated to have cost $164M in insured damage
The latest estimate of insured damage caused by a severe hailstorm that hit Calgary in July has nearly doubled from initial projections.
New data from Catastrophe Indices and Quantification places the cost of the damage caused by the storm at $164 million, a 78-per-cent increase from the original estimate of $92 million. The Insurance Bureau of Canada (IBC) said the increase comes after reported commercial losses rose significantly.
The July 13 storm's estimated damage has risen so dramatically in two months because of the large number of insurance claims that were filed, said Aaron Sutherland, a vice-president with the IBC, and the time needed to assess the damage reflected in thousands of claims.
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An estimate on the cost associated with the hailstorm that hit southern Alberta, including Brooks, in August, will be available in the coming weeks, the IBC said.
Wake-up call needed
The July storm's damage should be a wake-up call, Sutherland said.
Calgary lands inside of "Hailstorm Alley," a section of south-central Alberta that's hit with more than 40 hailstorms every year. He pointed to areas of northern Calgary, now filled by residential communities, which used to be occupied by agricultural land where crops suffered from hail damage.
Sutherland pointed to some Alberta properties that have multiple insurance claims from separate storms over the past four years, which is a situation he called unsustainable.
"We haven't necessarily built the right way," said Sutherland.
"Far too many homes have vinyl siding and asphalt shingles, and that stuff is just getting ripped to shreds — in some cases year after year after year — from hailstorms."
Numerous trees were downed during the storm on July 13, 2025, like this one in the northwest Calgary community of North Haven. (Colleen Underwood/CBC)
Sutherland said he believes hail-resistant roofing and siding should be mandated.
"It does add a little bit of cost on the front end if we are to mandate the use of hail-resistant roofing and siding, but I'll tell you one thing: the most expensive house you will ever buy is a house you have to rebuild twice," he said.
The IBC reports vehicle damage represented more than half of all insurance claims that came from the July storm. Sutherland argues this emphasizes the pressure that Alberta's auto insurance sector is feeling from increased severe weather events.
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Wind damage in hailstorms
While studying July's storm, the Northern Hail Project found powerful winds exacerbated the damage it caused. The research project, which operates out of Western University in London, Ont., found evidence of winds rising above 90 km/h in parts of Calgary, and evidence of wind damage in areas that also showed hail damage.
Northern Hail Project research meteorologist Simon Eng said there were reports of golf-ball-sized stones on the slope of Nose Hill and moving southeast toward Deerfoot Trail.
Eng said powerful winds can also cause smaller stones to create more damage than slightly larger hail acting only on the force of gravity.
"When you're seeing denting on the sides of vehicles, when you're seeing cracks on windows, when you're seeing damage to siding, that's where that added horizontal, sideways component to the hail trajectory is also exacerbating the impacts that you would see," said Eng.
He said the August storm in Brooks was an extreme example of this phenomenon, where they found evidence of winds that hit 150 km/h.
The IBC plans to release another updated estimate of the cost of July's hailstorm once six months have passed since the storm occurred.
Sutherland said he expects the insured damage caused by the Brooks hailstorm in August to cost tens, if not hundreds, of millions of dollars.
This article, written by Andrew Jeffrey, was originally published for CBC News.
Thumbnail image credit to John Koch via CBC News.