MONTREAL -- Canadian cities, led by Vancouver, dominate North America's Top Five list for quality of life, according to a survey issued by global business consultant Mercer.

Ottawa, Toronto and Montreal took the next three spots, followed by San Francisco, according to the 2014 Mercer Quality of Living rankings.

The only weakness in ranking Ottawa, Toronto and Montreal compared with Vancouver was their harsher winters, said Luc Lalonde, a principal at Mercer Canada.

"It basically boils down to climate because Vancouver has a relatively mild climate," Lalonde said Wednesday.

The study also looked at such factors as political stability, crime statistics, public and medical services, consumer goods and recreation. The quality of living index is used by companies to help determine compensation for their employees working abroad.

Ottawa ranked 14th globally, while Toronto was 15th and Montreal 23rd.

Globally, Vienna has been the top ranked city for the last three years, while Vancouver retained its fifth-place spot, Lalonde said.

Zurich was No. 2 worldwide for quality of life, followed by Auckland, New Zealand and Munich, Germany.

Lalonde said the rankings don't usually change dramatically from year to year.

"Wherever you have stability, good infrastructure and if the environment is politically and socially stable and if you have good public services, these things don't change overnight."

Cities with the lowest rankings in North America included Mexico City, financially troubled Detroit, St. Louis, Houston and Miami.

Although Miami and Houston are popular destinations, factors such as crime, air pollution and traffic congestion could have affected their scores, Lalonde said.

The city with the lowest ranking globally was strife-ridden Baghdad, followed by Bangui in Central African Republic and N'djamena in Chad.