Between January 4th and 10th, 1998, parts of Eastern Ontario and Western Quebec were hit by 3 successive storm fronts that have been called the greatest natural disaster in Canadian history. The storm's greatest impacts were profound and lengthy disruption to daily life and far-reaching economic consequences. The total precipitation, which fell as freezing rain, ice pellets and snow, exceeded 73 mm in Kingston, 85 mm in Ottawa and 100 mm south of Montreal. Canada's largest recorded ice storms, in Ottawa in December 1986 and Montreal in February 1961, left 30 to 40 mm of ice.

The ice storm began as a low-pressure warm front from Texas and a high-pressure Arctic cold front moving in simultaneously. When the air masses collided, the warm air rose, keeping the cold air down. Snow melted at mid-level; without time to freeze coming down, it froze on the ground. There was little wind to disrupt the patterns and no sun to thaw the ice between downpours.

The thickening ice downed power lines, forcing 100 000 people to seek refuge in hotels, private homes or hastily assembled shelters. Several thousand kilometres of power lines and telephone cables became useless. Personnel from 14 utility companies from 6 provinces and 8 American states worked to restore service. A state of emergency was declared. The Canadian Forces deployed nearly 16 000 troops in "Operation Recuperation," the largest-ever peacetime deployment. By comparison, the 1997 Red River and 1996 Saguenay flood relief efforts involved 8700 and 450 troops respectively.

The economic impact of the ice storm was estimated at over $1 billion. The Insurance Bureau of Canada reported 535 200 insurance claims after the storm, totalling approximately $790 million damage to homes, cars and other property. Canada's economic output declined by 0.7% in January, as business fell off in many industries. The combined changes in electric power and construction industries accounted for nearly 1/3 of January's overall drop in the GDP. Electric power systems alone dropped 14.2%. Overall, goods-producing industries fell 1.4%.

The geographic extent of the storm involved the area where nearly 1/4 of all Canada's dairy cows are located. There were 274 000 dairy cows in the areas of potential or actual power outages, 60% of them in Quebec. With no electricity to operate milking machines, cows could not be milked, making them vulnerable to mastitis, an inflammation of the udder. Where cows could be milked, many processing plants had no, or limited, power; farmers had to dump over 10 million litres of milk, valued at $5-6 million. Canadian farmers were able to send 1.5 million litres of milk to American facilities, which was subsequently returned for Canadian consumption. Although the decline in dairy production was relatively small, there is still concern that the dairy cows affected will never regain their pre-storm productivity levels.

The maple syrup industry was also seriously affected. Over 22% of all Canadian maple syrup taps bore the weight of over 40 mm of ice, including over 23% of Quebec's 21 million taps and 285 000 in Ontario. Quebec's maple syrup industry produces 70% of the world supply. The number of taps was sharply reduced. Millions of tree branches were damaged, seriously affecting sap flow. Domestic sugar maples grow larger than their natural counterparts, giving them more potential for ice damage. Falling branches and ice build-up damaged many of the pipes that channel sap. The Ontario Maple Syrup Producers Association estimated that it could take up to 40 years for eastern Ontario's production to return to normal.

See also Weather, Rainfall Extremes and Disasters. Statistics Canada, for statistics and maps of areas affected.